Nokia Flexi EDGE BTS Feature Descriptions

Nokia Flexi EDGE BTS FeatureDescriptions

DN70124104Issue 1-0 en draft

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2 (63) # Nokia Corporation DN70124104Issue 1-0 en draft

Nokia Flexi EDGE BTS Feature Descriptions

Contents

Contents 3

1 Overview of features in Nokia Flexi EDGE BTS SW release EP1 5

2 Data/Voice 72.1 BSS20088 Dual Transfer Mode 72.2 BSS9006 General Packet Radio Service (GPRS) 112.3 EGPRS 122.3.1 BSS10083 Enhanced General Packet Radio Service (MCS 1-9) 122.3.2 BSS10045 Dynamic Abis allocation 162.4 BSS10074 Support of PBCCH/PCCCH 172.5 BSS7003 High Speed Circuit Switched Data and BSS7037 14.4 kbit/s

Data Services 182.6 BSS10004 Adaptive Multi Rate Codec (AMR) 202.7 BSS7005 Intelligent Frequency Hopping and BSS6114 Intelligent

Underlay-Overlay 22

3 Interworking 233.1 BSS10101 GSM-WCDMA Interworking 233.2 BSS11086 Support for Enhanced Measurement Report 25

4 Operability 274.1 BSS11047 Intelligent shutdown for Flexi EDGE BTS 274.2 Remote mode of Nokia Flexi EDGE BTS Manager 284.3 BSS10063 Rx Antenna Supervision by Comparing RSSI 304.4 BSS9068 BTS SW management 304.5 BSS9067 Runtime diagnostics and BTS alarms 314.6 BSS9063 Abis loop test 324.7 BSS9062 BTS supervision 324.8 BSS9061 Temperature control system 334.9 BSS9060 TRX Test 334.10 TRX Loop Test 354.11 BSS9059 Nokia BTS resets 354.12 BSS9058 BTS fault recovery 364.13 BSS9056 Autodetection of site configuration 364.14 BSS9003 Power system management for Site Support/IBBU (from Nokia

NetAct) 36

5 Site solutions 395.1 BSS10046 Multi BCF Control 395.2 BSS9055 Clock Synchronisation between Base Stations 405.3 BSS10069 Synchronised BSS 425.3.1 BSS20371 BSS Site Synchronisation Recovery Improvement 425.3.2 BSS11073 Recovery for BSS and Site Synchronisation 435.4 Operating bands 455.5 BTS2043 BTS External Alarms and Controls (EAC) 465.6 BTS2020 RX antenna diversity 47



Contents

6 Basic GSM operation 496.1 Basic GSM features 496.2 BSS6071 Enhanced Full Rate Codec 496.3 BSS6025 Short Message Service Cell Broadcast with Discontinuous

Receiving (SMS-CB DRX) 506.4 BTS2503 Compressed Abis timeslot allocation 516.5 BTS2133 Short Message Service (SMS) point-to-point 516.6 BTS2067 Fast Associated Control Channel (FACCH) Call Setup 526.7 BTS2037 Air interface measurement pre-processing 526.8 BTS2033 Short message cell broadcast 526.9 BTS2024 Synthesised frequency hopping 526.10 BTS2023 Downlink and uplink DTX; TCH/FS, speech 536.11 BTS2013 Baseband Frequency Hopping 536.12 BTS2012 BTS time base reference from PCM 536.13 BSS7036 Dynamic SDCCH Allocation 53

7 Transmission 557.1 Basic transmission 557.1.1 Abis Trunk Transmission for E1 (ETSI) interface 557.1.2 Abis Trunk Transmission Allocation for T1 (ANSI) Interface 557.1.3 Abis Trunk Signalling 567.1.4 Network Synchronisation 567.1.5 Support for Nokia Microwave Radio Links 577.1.6 BSS9065 Transmission Operability 577.2 Transmission solutions 587.2.1 Q1 Interface Between the BSC and Transmission Equipment 587.2.2 PDH traffic routing 587.2.3 Abis loop protection 597.2.4 Redundant Abis Trunk 61

Appendix A Other features 63A.1 Other features 63



1 Overview of features in Nokia FlexiEDGE BTS SW release EP1

Operating and Application SW

Nokia BSS12 Software consists of Operating Software and Application Software:

. Operating Software refers to basic functionalities of a product.

. Application Software refers to optional features.

The BSS12 system features are available in the following network elementreleases: S12, EP1.

For more information on the features, see Nokia GSM/EDGE BSS SystemDocumentation and Nokia BSC/TCSM Product Documentation sets.

For general guidelines related to licensing, see BSS Licensing in the BSS SystemDocumentation.



Overview of features in Nokia Flexi EDGE BTS SW release EP1

2 Data/Voice

2.1 BSS20088 Dual Transfer Mode

Dual Transfer Mode (DTM) provides mobile users with simultaneous circuit-switched (CS) voice and packet-switched (PS) data services. This means thatusers can, for example, send and receive e-mail during an ongoing phone call.Figure E-mail in dual transfer mode illustrates how a DTM user can have a voicecall while downloading e-mail messages. Figure Real time video sharing in dualtransfer mode illustrates how two DTM users share a video call.



Data/Voice

Figure 1. E-mail in dual transfer mode

CS voice call

PS stream

BTS

Packet core

BTS

DTMuser 3

non-DTM MS

BSC/PCU

MSC/HLR

BSC/PCU

Mail server

IP backbone



Figure 2. Real time video sharing in dual transfer mode

In dual transfer mode, the mobile station (MS) is simultaneously in dedicatedmode and in packet transfer mode so that the timeslots allocated for each MS areconsecutive and within the same frequency. In dedicated mode, the MS has a CSconnection. In packet transfer mode, the MS has a PS connection. The CSconnection is always a single slot connection, whereas the PS connection can alsobe a multislot connection.

An MS is in dual transfer mode when it has simultaneous CS and PS connections.An MS can enter dual transfer mode only through dedicated mode. If the MS is inidle mode, it moves to dedicated mode before entering dual transfer mode. If theMS is in packet transfer mode, the PS connection is released before the MSmoves to dedicated mode. The packet control unit (PCU) or the MS re-establishesthe PS connection as soon as the MS has a CS connection.

CS voice call

PS stream

BTS

Packet core

BTS

DTMuser 1

DTM user 2

BSC/PCU

MSC/HLR

BSC/PCU

IMS

IP backbone



Data/Voice

If a CS connection is released when the MS is in dual transfer mode, also the PSconnection is released. The PCU or the MS re-establishes the PS connection assoon as the CS channel release has been completed. If a PS connection is releasedwhen the MS is in dual transfer mode, the MS returns to dedicated mode. The MSreturns to idle mode when it has neither a CS nor a PS connection. Figure DTMstate transitions illustrates how an MS can move from one mode to another.

Figure 3. DTM state transitions

Interaction with other features

The DTM supports all full rate speech codecs:

. Full Rate (FR)

. Enhanced Full Rate (EFR)

. Adaptive Multi Rate/Full Rate (AMR/FR)

RR idle mode/Packet idle mode

Packet transfermode

Dedicatedmode

Dual transfermode

PS release

CS release

DTM assignment



The CS speech codec selection for DTM is similar to the one used for a plain CSconnection. In addition, the DTM/PS channels can be multiplexed similar tonormal GPRS/EDGE.

Benefits

With DTM, you can expand your service portfolio to offer users enhancedservices in a GSM/EDGE network. DTM allows you to provide a wide range ofservices that demand a simultaneous CS and PS connection. Mobile users can usedata services, such as file transfer, web browsing, video sharing, and mobilenetmeeting, during a speech call. This makes it possible to launch services similarto UMTS class A services also in 2G networks. In addition, these services can beused to complement the 3G coverage in places where there is no 3G networkcoverage.

2.2 BSS9006 General Packet Radio Service (GPRS)

General Packet Radio Service GPRS provides packet radio access for GSMmobile stations.

By sharing the channels provided by various network elements and transmissionsystems, the cellular network resources are used more efficiently for data servicesthan with circuit switched data services.

All mobile stations share the radio resources in a cell, and use the radio resourcesonly when sending or receiving data.

The Channel Coding Unit (CCU) in the BTS performs the channel coding for thefollowing ETSI defined coding schemes:

. Channel Coding Scheme 1 (CS-1) 9.05 kbit/s




In a packet transfer mode, the mobile station must use the continuous timingadvance procedure. This procedure is carried out on all packet data channels(PDCHs).

Coding Schemes CS-3 and CS-4 (BSS11088) is an application software product,and it requires a valid licence in the BSC. CS-3 and CS-4 provide a considerablegain in data rates for GPRS mobile stations not supporting EGPRS (themandatory RLC header octets are excluded from the data rate values).



Data/Voice


CS-3 and CS-4 do not fit to one 16kbit/s Abis/PCU channel and require the use ofDynamic Abis Allocation.

2.3 EGPRS

2.3.1 BSS10083 Enhanced General Packet Radio Service (MCS 1-9)

Enhanced General Packet Radio Service (EGPRS) supports high rate packet dataservices across varying channel conditions. EGPRS is built on top of the packetswitched data service, GPRS. As the table below shows, EGPRS supports higherdata rates compared to the basic GPRS, using several Modulation and CodingSchemes (MCSs). The speed in radio resources is fixed for GMSK and 8PSK, butbecause the amount of channel coding varies, the user data rate varies dependingon the MCS.

Table 1. Peak data rates for single slot EGPRS

MCS Modulation Code Rate Family User Rate

1 GMSK .53 C 8.8 kbps

2 GMSK .66 B 11.2 kbps

3 GMSK .80 A 14.8 kbps

4 GMSK 1 C 17.6 kbps

5 8PSK .37 B 22.4 kbps

6 8PSK .49 A 29.6 kbps

7 8PSK .75 B 44.8 kbps

8 8PSK .92 A 54.4 kbps

9 8PSK 1 A 59.2 kbps

Gaussian Minimum Shift Keying (GMSK) modulation provides the robust modefor wide-area coverage, while 8 Phase Shift Keying (8PSK) provides higher datarates.

The MCSs are organised into families to allow a re-segmentation of the datablock for link adaptation. Since higher protection means lower throughput, theprotection that best fits the channel condition is chosen for maximum throughput.



Incremental Redundancy (IR)

Incremental Redundancy (IR) is an efficient combination of two techniques:Automatic Repeat reQuest (ARQ) and Forward Error Correction (FEC). In theARQ method, when the receiver detects the presence of errors in a received datablock, it requests a re-transmission of the same data block from the transmitter.The process continues until an uncorrupted copy reaches the destination. TheFEC method adds redundant information to the user information at thetransmitter, and the receiver uses the information to correct errors caused bydisturbances in the radio channel.

In the IR scheme (also known as Type II Hybrid ARQ scheme), only a smallamount of redundancy is sent first, which yields a high user throughput if thedecoding is successful. However, if the decoding fails, a re-transmission takesplace according to the ARQ method. Using IR, the re-transmission of the datablock is different from the initial transmission. The transmitter sends additionalredundancy that is decoded at the destination with the previously receivedinformation to allow for error correction. Since the combination includes moreinformation than any individual transmission, the probability of correct receptionis increased.

The IR mechanism in EGPRS is designed around nine Modulation and CodingSchemes (MCSs). The basic characteristics of each MCS are its fixed data rateand fixed protection level. For each of the MCSs, it is possible to reach the samedata rate with the same protection level, but with a different protection scheme.



Data/Voice

Figure 4. Incremental Redundancy scheme

There are three protection schemes (P1, P2 and P3) for an MCS, as shown in thefigure above. The data block is first protected with the P1 of a certain MCS, andsent over the air to the receiver, which tries to recover the data. If this phase fails,the received P1 is stored in the receiver's memory for future use, and thetransmitter sends the data block protected with the P2 of the same MCS. Thereceiver combines the received P2 with the stored P1 and tries to recover the datafrom the combination of P1 and P2.This process continues until the data isrecovered.

If after P3, the data still cannot be recovered, P1 is sent again and combined withthe stored P1, P2 and P3 (which reaches a protection level of about four timesP1), and so on until the data is recovered.

Data Block

One MCSP2 P3P1

P2

P2

P2

P1

P1

P1

P1

Stored

Stored

Receiver

Transmitter

No data

recovered

No data

recoveredCombination: Protection Level x 2

Protection Level 1

Combination: Protection Level x 3

Stored

P3

P3

1st transmission 1st re-transmissionupon reception failure

2nd re-transmissionupon reception failure



Link Adaptation (LA)

The Link Adaptation (LA) mechanism works to provide the highest throughputand lowest delay available by adapting the protection of the information to besent according to the link quality. The upcoming channel quality is accuratelypredicted from various measurements of the past link. This prediction determinesthe relevant protection of the information to be sent. Therefore, enabling LArequires accurate link quality measurements and a set of Modulation and CodingSchemes (MCSs) with different degrees of protection.

The use of new efficient EGPRS measurements provides an accurate predictionof the upcoming link quality in several propagation channels with various speeds(such as typical urban and rural areas, and hilly terrain).

Nine Modulation and Coding Schemes (MCSs) are designed for EGPRS. When adata block is sent, the information is encoded, using one of the MCSs, to resistchannel degradation, and modulated before transmission over the air interface.Because the resources are limited, the higher the level of protection forinformation, the less information is sent. MCS-1 to MCS-9 range from a highprotection/low bit rate, to no protection/high bit rate, as summarised in the figurebelow.

Figure 5. Data rates and protection levels for Modulation and CodingSchemes

With EGPRS, it is possible to switch between any of the MCSs, from one datablock to another, as it is with GPRS. However, with GPRS, once a data block issegmented to fit one particular coding scheme, it is not possible to switch thecoding scheme on reception failure, and therefore the re-transmission takes place

MCS-1 .53 C

59.2

Scheme Code Rate FamilyData Rate (kbps)

Protectiondecreases

Modulation

MCS-2 .66 B

54.4

MCS-3 .80 A

44.88PSK

MCS-4 1 C

29.6

MCS-5 .37 B22.4

MCS-6 .49 A

17.6

MCS-7 .76 B

14.8GMSK

MCS-8 .92 A

11.2

MCS-9 1 A

8.8



Data/Voice

with exactly the same protection as for its initial transmission. With EGPRS, it ispossible to change the MCS. This is useful, as the level of protection needed inre-transmission may be different because of varying channel conditions and theexisting protection from earlier incremental redundancy transmissions.

2.3.2 BSS10045 Dynamic Abis allocation

Dynamic Abis provides an efficient transport mechanism for GPRS and EGPRSto use more than one 16 kbps subchannel on the Abis interface for each packetdata channel (PDCH) on the Air interface. The continuous areas of PCMtimeslots on PCM links are configured as Dynamic Abis pools (DAP) to providethe needed capacity.

Each logical TRX utilising Dynamic Abis is associated with a DAP in addition tothe standard fixed traffic channel (TCH) area. Any packet data channel would becontinuously using a master PCU channel located on a fixed area. Depending onthe traffic load on each Air interface channel, more capacity would be allocatedfrom the DAP. See the table below for the number of 16 kbps DAP subchannelsused with each CS and MCS.

Table 2. Number of 16 kbps DAP subchannels used with each CS and MCS

CS/MCS Number of DAPsubchannels

CS1 0

CS2 1

CS3 1

CS4 1

MCS-1 0

MCS-2 1

MCS-3 1

MCS-4 1

MCS-5 1

MCS-6 2

MCS-7 3

MCS-8 4

MCS-9 4



The PCU controls the downlink and uplink slave allocation on a radio blockbasis. Any 20 ms period on Abis is controlled based on real traffic demand.Downlink and uplink allocations are controlled separately. The slave allocation isinformed to the BTS by in-band signalling on the corresponding downlink masterchannel.

Multiple logical TRXs can share a DAP. Multiple DAPs can be configured foreach BTS and for each physical Abis link.

O & M signalling, TRX signalling, and circuit-switched channels are used withDynamic Abis in the same way as they are used with the Nokia conventionalAbis solution.

2.4 BSS10074 Support of PBCCH/PCCCH

Support of Packet Broadcast Control Channel/Packet Common Control Channel(PBCCH/PCCCH) allows dedicated common control channel (CCCH) capacityfor (E)GPRS services.

Packet common control channel (PCCCH) comprises logical channels for packetcommon control signalling. The following common control channels areavailable:

. Packet random access channel (PRACH) is used by a mobile station (MS)to initiate an uplink transfer for sending data or signalling information. APacket Access burst and Extended Packet Access burst are used on thePRACH.

. Packet paging channel (PPCH) is used to page an MS before a downlinkpacket transfer. The PPCH uses paging groups to allow the usage of DRX(discontinuous reception) mode. The PPCH can be used for paging of bothcircuit-switched (CS) and packet data services. The paging for CS serviceson the PPCH requires a Gs interface between an MSC and SGSN.

The Nokia implementation is based on the Network Mode of Operation I(NOM I). The network sends a CS paging message for a GPRS-attachedMS, either on the same channel as the GPRS paging channel, or on aGPRS traffic channel. This means that the MS only needs to monitor onepaging channel, and that it receives CS paging messages on the packet datachannel when it has been assigned a packet data channel.



Data/Voice

. Packet access grant channel (PAGCH) is used in the packet transferestablishment phase to send a resource assignment to an MS before apacket transfer.

. Packet broadcast control channel (PBCCH) broadcasts packet-data-specificSystem Information (for example C31 and C32 cell selection criteria). C31/C32 are used to direct GPRS traffic on the cells, which can serve EGPRSmost efficiently and interference free to CS traffic. C31/C32 apply in cellsusing PBCCH/PCCCH, otherwise the existing C1/C2 are used.

If the PBCCH is not allocated, the packet-data-specific system informationis broadcast on the BCCH.

PCCCH/PBCCH is mapped to its own timeslot. This should be configured on thesame TRX as the BCCH.

Support of PBCCH/PCCCH requires PCU1 with S12. The feature cannot be usedwith PCU2.

2.5 BSS7003 High Speed Circuit Switched Data andBSS7037 14.4 kbit/s Data Services

High Speed Circuit Switched Data uses multiple parallel channels to providehigher data rates for end-user applications, such as the World Wide Web (www),file transfer and facsimile.

The BSS implementation is to reserve a multiple set of basic resources for onehigh-speed data call. The data rate and the number of reserved timeslots varybetween one and the defined maximum of the user application. The variable rateis needed for various common procedures, for example for handovers to a newcell if the requested data rate cannot be given immediately. The BSSimplementation of HSCSD supports the simultaneous usage of a maximum of 4radio timeslots (RTSLs) per HSCSD call.

The table below presents the corresponding maximum data rates with differentchannel coding.

Table 3. Corresponding maximum data rates with different channel coding

Number of RTSLs 9.6 kbit/s 14.4 kbit/s

1 9.6 kbit/s 14.4 kbit/s





Table 3. Corresponding maximum data rates with different channel coding(cont.)

Number of RTSLs 9.6 kbit/s 14.4 kbit/s


Both asynchronous and synchronous bearer services and transparent and non-transparent data services are supported. Transparent HSCSD uses fixed data ratethroughout the duration of the call, but with non-transparent HSCSD, the datarate can be changed automatically during the call, because of increased traffic forexample. The radio interface is either symmetric or asymmetric according to themobile station (MS) capability.

During basic channel allocation, the system tries to keep consecutive timeslotsfree for multichannel HSCSD connection. If there are not enough appropriate freechannels to fulfil the requested data rate, a non-transparent HSCSD connection isstarted with fewer channels than requested. At least one channel is allocated for anon-transparent HSCSD call request if there are available resources in the cell. Byuse of the resource upgrade procedure, the data rate of the HSCSD connectioncan be increased when an appropriate channel is available.

In a congested cell, the HSCSD load can be adjusted by BSC parameterisation.The resource downgrade procedure is used to lower the HSCSD connection datarate to release radio channels for other connections. If a transparent connectioncannot be established in a cell, a directed retry can be attempted.

BSS7037 14.4 kbit/s GSM Data Services

With the 14.4 kbit/s GSM Data Services, the speed of one timeslot increases from9.6 kbit/s to 14.4kbit/s.

The 14.4 kbit/s channel coding has less error correction than 9.6 kbit/s coding.Therefore, there are some areas on the cell edges where using 9.6 kbit/s codingwill give a higher data throughput. The figure below shows the results of Nokiasimulations. Note that for transparent mode the maximum user throughput is 14.4kbit/s, but in non-transparent mode, the maximum user throughput is 13.2 kbit/s.The maximum throughput is based on the amount of available space in the codingblock. Non-transparent data requires space for error checking, but transparentdata does not.



Data/Voice

Figure 6. Typical data throughputs for 14.4 kbit/s (non-transparent) and 9.6kbit/s coding (this depends on the NW radio conditions)

The Automatic Link Adaptation (ALA) optimises the data throughput byautomatically choosing the channel coding most suitable to the radio conditionsand by control of the power levels.

The 14.4 kbit/s Data Services can be combined with High Speed Circuit SwitchedData (BSS7003).

2.6 BSS10004 Adaptive Multi Rate Codec (AMR)

Adaptive Multi Rate Codec (AMR) consists of a set of codec modes and anadaptive algorithm for codec changes, which can provide a significantly betterspeech quality. With AMR, it is possible to increase speech capacity by using thehalf rate mode, and still maintain the quality of current FR calls.

AMR consists of 8 different speech codec modes with a total of 14 channel codecmodes, which are listed in the following table:

0

2

4

6

8

10

12

14

60 65 70 75 80 85 90 95 100

Percentage of Cell Area (%)

DataThroughputRate(kbit/s)

14.4

9.6



Table 4. Channel and speech codec modes for AMR

Channelmode

Channelcodecmode

Source coding bit-rate,speech

Net bit-rate,in-bandchannel

Channelcoding bit-rate, speech

Channelcoding bit-rate, in-band

TCH/FR CH0-FS

CH1-FS

CH2-FS

CH3-FS

CH4-FS

CH5-FS

CH6-FS

CH7-FS

12.20 kbit/s (GSMEFR)

10.20 kbit/s

7.95 kbit/s

7.40 kbit/s (IS-641)

6.70 kbit/s

5.90 kbit/s

5.15 kbit/s

4.75 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

10.20 kbit/s

12.20 kbit/s

14.45 kbit/s

15.00 kbit/s

15.70 kbit/s

16.50 kbit/s

17.25 kbit/s

17.65 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

0.30 kbit/s

TCH/HR CH8-HS

CH9-HS

CH10-HS

CH11-HS

CH12-HS

CH13-HS

7.95 kbit/s (*)

7.40 kbit/s (IS-641)

6.70 kbit/s

5.90 kbit/s

5.15 kbit/s

4.75 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

3.25 kbit/s

3.80 kbit/s

4.50 kbit/s

5.30 kbit/s

6.05 kbit/s

6.45 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

0.10 kbit/s

(*) Not supported, requires 16 kbit/s TRAU.

Codec mode adaptation for AMR is based on received channel quality estimationin both the mobile station (MS) and BTS, followed by a decision on the mostappropriate speech and channel codec mode to apply at a given time. In high-error conditions, more bits are used for error correction to obtain error robustcoding, while in good transmission conditions, only a small number of bits isneeded for sufficient error protection and more bits can be allocated for sourcecoding.

An in-band signalling channel is defined for AMR that enables the MS and theBTS to exchange messages on applied or requested speech and channel codecmodes. The above mentioned selected speech codec mode is then sent, by usingthe in-band signalling channel, to the transmitting side, where it is applied for theother link. The BTS commands the MS to apply a particular speech codec modein the uplink, but the MS can only request the BTS to apply a particular speechcodec mode in the downlink because the BTS has an option to override the MS'srequest. For each codec mode set there is an associated set of decision thresholdsfor mapping the channel quality measurements to the Mode Commands/Requests.



Data/Voice

2.7 BSS7005 Intelligent Frequency Hopping andBSS6114 Intelligent Underlay-Overlay

With Intelligent Frequency Hopping and Intelligent Underlay-Overlay, it ispossible to reuse frequencies more intensively, and therefore achieve a higherradio network capacity. With Intelligent Frequency Hopping, it is also possible toavoid frequency dependent fading on the radio path.

When Intelligent Frequency Hopping is in use, you can use Intelligent Underlay-Overlay simultaneously with frequency hopping in the same cell. You can useeither baseband (BB) or radio frequency (RF) hopping.

The different interference characteristics of the regular and super-reuse layers inIntelligent Underlay-Overlay require that the network plan for frequency hoppingis constructed separately for each layer. Intelligent Frequency Hopping allows theuse of separate Mobile Allocation Frequency Lists of radio frequency hopping forthe layers of an Intelligent Underlay-Overlay cell. Baseband hopping isimplemented by treating the regular layer as a normal cell and the super-reuselayer as a new hopping group.

You can set the regular and super-reuse layers in Intelligent Underlay-Overlayindividually to hopping.



3 Interworking

3.1 BSS10101 GSM-WCDMA Interworking

In order for an operator to provide seamless coverage in areas where WCDMA isnot available, such as rural areas, inter-system handovers are introduced. Thisfeature facilitates handovers between GSM BSS and WCDMA RAN. When theWCDMA and GSM networks overlap, also an inter-system handover from GSMto WCDMA can be made to release traffic load in the GSM system.

Benefits of the inter-system handover include:

. seamless coverage extension for 3G with the existing GSM network orvice versa

. capacity extension for GSM with load sharing between 3G and GSM

. 3G services to all dual-mode subscribers

Both the circuit switched (handover and MS cell re-selection) and packetswitched (MS cell re-selection and Network controlled cell re-selection) modesare supported.

In idle mode, thresholds for a mobile to select the best cell (MS cell re-selection)are based on field strength. The main principles in the idle mode cell re-selectionare:

. the operator is able to define the cell re-selection thresholds by RadioNetwork (RNW) parameters

. those parameters are sent to the mobile in the System Information (SysInfo) or Packet System Information messages

For initial cell re-selection, the system information broadcast indicates that dualmode capable mobiles should select a certain BSS.

Coverage based handovers (from WCDMA to GSM) combined with load basedhandovers (from GSM to WCDMA) are supported from BSS10.5 onwards.



Interworking

Figure 7. Load and coverage reason handovers

In handover preparation, the controller (RNC or BSC) commands the mobile tomeasure the neighbouring cells belonging to other systems. The mobile sends theinter-system measurement results to the RNC or BSC. Based on the measurementresults, the BSC or RNC handover algorithm is able to decide whether to initiatean inter-system handover or not.

A handover attempt from GSM to WCDMA is initiated:

. if the signal strength of the adjacent WCDMA cell is greater than theoperator defined threshold

. if the load of the serving GSM cell exceeds the load threshold for speechand transparent data calls

GSM highloaded

WCDMA lowloaded

Mobile moving

Load and Coverage Reason HandoverCircuit Switched traffic

Load reasonhandover for speech

GSM

GSM

GSM GSM GSM

WCDMA WCDMA

WCDMA GSM

GSM can be used to extendWCDMA coverage area

WCDMA can be usedto relieve GSM overload

Load reasonhandover

Coverage reasonhandover



A handover from WCDMA to GSM is seen as an inter-BSC handover in thetarget system. Cell re-selection is performed by a Mobile Station (MS)autonomously. Parameters C32/C31, which are broadcast on PBCCH, areprovided as a complement to the current GSM Packet Switched cell re-selectioncriteria.

3.2 BSS11086 Support for Enhanced MeasurementReport

Support for Enhanced Measurement Report (EMR) provides the system withenhanced serving and neighbour cell measurements. This is achieved byrequesting the mobile station (MS) to use the EMR for reporting downlinkmeasurements.

Enhanced Measurement Report also provides the system with information suchas Downlink Frame Erasure Rate (DL FER), the usage of bit error probability(BEP) instead of RX Quality during the DTX frames, and the support forreporting WCDMA RAN neighbour cells. In addition, the EMR also provides anextended range for the serving and neighbour cells downlink signal strength andthe possibility to report altogether up to 15 GSM and/or WCDMA RANneighbour cells in one report.

These reports can be used by the network to enhance the generic performance ofthe existing system, enable GSM/WCDMA interworking, and enhance severalNokia features, such as:

. Automated Planning

. Dynamic Frequency Channel Allocation (DFCA)

. FER Measurement

. Intelligent Underlay Overlay (IUO) and Intelligent Frequency Hopping(IFH)



Interworking

Interaction with other features:

. The network does not order an MS to use the EMR for reporting when anIdle Broadcast Control Channel (BCCH) Allocation List or a MeasurementBCCH Allocation List is used in active state in the serving cell.

. With Common BCCH Control, when a call is in a non-BCCH frequencyband, the serving cell BCCH frequency is added to the BCCH frequencylist.

. When the EMR is used for reporting, also the serving cell BSIC is added tothe BSIC list before sending it to an MS.

Benefits

. Improved generic performance of the system

. Enables GSM/EDGE/WCDMA interworking

. Improved performance of statistics



4 Operability

4.1 BSS11047 Intelligent shutdown for Flexi EDGE BTS

To provide protection against a mains power break, you can equip a BTS with abattery backup system. The purpose of Intelligent Shutdown is to maintain theBTS site operation for as long as possible by reducing capacity (units turned offor reduced to low power consuming modes) so that only the essential sitefunctions are maintained.

The BSC controls the reduction of the site capacity, which commands individualtransceiver units to be shut down or started up.

On a BTS site basis, you can define the service level of the site to be maintainedwhile the battery backup is in use. You can also define two timers, allowing theexecution of the shutdown procedure in phases, reducing capacity in a controlledway. Three service level options are available:

. Full service – Service is maintained at full capacity for as long as thebattery power supply lasts. The two timers are ignored.

. Broadcast control channel (BCCH) backup – The BTS maintains fullcapacity until the first timer expires. After that, all active calls on non-BCCH transceivers are handed off. The non-BCCH transceivers areblocked from carrying any new calls and the BSC commands the BTS toshut them down. The BCCH TRX(s) are maintained to offer minimumservice.

. Transmission backup – The second timer starts after the first one hasexpired. After the expiry of the second timer, all active calls on BCCHtransceivers are handed off. The BCCH transceivers are blocked fromcarrying new calls and the BSC commands the BTS to shut them down.Only the BTS transmission equipment power is maintained to secure thefunctionality of a transmission chain for as long as the batteries last.

When the mains power is restored, the BSC commands the BTS site to power allthe shut down equipment and return back to full service.



Operability

Battery backup configurations for Flexi EDGE BTS:

. Nokia Flexi Support

. Flexi with Integrated Battery Backup Units

. 3rd Party Battery Backup Solution

Nokia Flexi EDGE BTS autodetects the Flexi Support system and the integratedbattery backup units. When using a 3rd party battery backup solution, an externalalarm line is designated to indicate a mains power loss/restoration from thatequipment. This is specified in the configuration data that the BSC sends to theBTS during the initial start-up or reset of the BTS. If the mains power is lost, thebattery backup system sends a 'mains breakdown' alarm to the BTS, and further tothe BSC, which then triggers the shutdown procedure.

Benefits

The operation is optimal during both short and long mains breaks. Timers allowexecuting the shutdown procedure in several phases. Each phase reduces thebattery power consumption.

With intelligent shutdown you can define the service level to be applied on amains failure to optimise the trade-off between the service level and batterypower lifetime. A short mains break will not reduce the service unnecessarily,whereas during a longer break, the essential functions, such as BCCH ortransmission chain, are maintained for as long as possible.

4.2 Remote mode of Nokia Flexi EDGE BTS Manager

You can control Nokia Flexi EDGE BTS equipment locally via Nokia FlexiEDGE BTS Manager. To minimise the need for site visits, you can also accessNokia Flexi EDGE BTS Manager functions remotely.

You can monitor and test the BTS remotely, by connecting the Flexi EDGE BTSManager to the BTS remotely via NetAct. A PC with Flexi EDGE BTS Managersoftware is used as a user terminal. Nokia General Communication Server (GCS)SW Suite is used for providing both local and remote connections to the BTS.



Figure 8. Nokia Flexi EDGE BTS Manager connected in remote mode

You can connect to a remote BTS using the Flexi EDGE BTS Managerapplication, via a menu item and/or a toolbar button, or via the command line.The user interface of Flexi EDGE BTS Manager informs you of the remoteconnection status when information is being requested from the remote BTS, andwhen the Flexi EDGE BTS Manager is processing received information from aremote BTS. Nokia Flexi EDGE BTS Manager connected in remote modesupports all other features available via a local connection, except the ControlAbis interface (enable/disable) and the 'block' and 'deblock' commands.

It is not possible to perform the initial BTS commissioning remotely, but it ispossible to perform subsequent recommissioning or append commissioning fromthe Flexi EDGE BTS Manager in remote mode.

At the BTS, the messages sent from or to the Flexi EDGE BTS Manager inremote mode are re-routed, but handled in the same way as with the localconnection.

TRX

OMU

BTS

TRX

OMU

BTS

NetAct

BSC

NetActEthernetLAN

Ethernet

BTS Manager,remote

connection

BTS Manager,remote

connection

BTSManager, localconnection



Operability

4.3 BSS10063 Rx Antenna Supervision by ComparingRSSI

The purpose of Rx Antenna Supervision by Comparing RSSI is to monitor the Rxantenna condition. Rx antennas can be monitored for major problems by taking along-term average of the difference between the Main Rx RSSI and the Div RxRSSI. This feature provides continuous antenna supervision for the BTSs, whichhave the Main Rx RSSI and the diversity in use. It also offers an alternativesolution for Tx monitoring in cells that use duplexing. This detects, for example,antennas with poor VSWR and inadequate feeders.

The monitoring is based on the principle that all received bursts, where the Rxlevel of main or diversity branch is above the defined limit value (-100 dBm), areaccepted as samples and used in the averaging process. A minimum of 160,000samples in one hour must be collected for the BTS to assume that the results arereliable and therefore could be used to raise an alarm.

The differences of the TRXs connected to the same antennas are counted up, andthe average difference for main and diversity antennas is calculated. If thedifference is above the threshold (default value 10 dB), and the number ofsamples indicate that the results should be reliable, an alarm is activated. Thethreshold default value of 10 dB can be changed by a parameter at the BSCbetween 3 and 64. The functionality of the feature can be disabled.

It is still possible that both antennas are damaged simultaneously and thedifference algorithm cannot detect the fault. For this reason, the BSC alsoobserves the assignment and handover success rate.

Benefits

Rx Antenna Supervision by Comparing RSSI can identify antenna problemswithout the need for active tests.

4.4 BSS9068 BTS SW management

You can update the BTS software by downloading new BTS software remotelyfrom the BSC. Site visit is not needed. You can also download the BTS softwarewith Nokia Flexi EDGE BTS Manager.

You can download BTS sofware during normal operation. Resetting the siteactivates the BTS software. This makes it possible to update the BTS softwarewith minimal BTS downtime.



Downloaded BTS software application files are stored in the flash memory of theSystem Module (ESMA). The flash memory of the System Module can containtwo BTS SW versions.

Software downloading is executed after BCF reset if the System Module does nothave the correct software. The BTS software can also be background downloadedto the System Module when a BTS software package is being deployed to theBCF.

Local BTS SW backup minimises BTS boot-up time because there is no need todownload the BTS software package from the BSC after each reset.

4.5 BSS9067 Runtime diagnostics and BTS alarms

Alarm diagnostics filters alarms, reporting only those alarms that directly affectthe BTS service level, that is, BTS level alarms. Only one critical alarm per objectcan be active at a time.

When the fault causing the alarm has been corrected, or a faulty module has beenreplaced, the alarm is cancelled either manually or automatically.

When the BSC displays a BTS alarm, the alarm text includes a fault reasondescribing the cause of the alarm. You can use this information introubleshooting. For more information, see Trouble Management of Nokia FlexiEDGE BTS.

TX antenna VSWR measurement

Nokia Flexi EDGE BTS can provide broadcast control channel (BCCH) antennasupervision by VSWR monitoring. There are minor and major VSWR alarmlimits, and the user sets these limits during commissioning. If the VSWR exceedsthe limit, this indicates a problem in the cable path between the BTS antenna portand the antenna. Typical causes for this are broken cables, broken connectors, andthe ingress of water in the antenna cable path.

The BCCH antenna can only be supervised reliably if the BCCH power level iswithin the acceptable range of power levels (0 to 6). Alarm handling softwarepolls VSWR alarms every 10 seconds. If five (5) consecutive polls show that thealarm is active and the BCCH power level is within the acceptable range, thealarm is considered to be real, and it is reported to the BSC and Nokia FlexiEDGE BTS Manager.



Operability

VSWR alarms are handled as TRX object level alarms. When a VSWR alarm isconsidered to be real, an alarm 7606 'TRX faulty' (when the major VSWR limit isexceeded) or alarm 7607 'TRX operation degraded' (when the minor VSWR limitis exceeded) is reported for all TRXs that have their TX or RX path defined in theBTS configuration to be connected to an antenna with an active VSWR alarm.

4.6 BSS9063 Abis loop test

The Abis Loop Test verifies the Abis transmission setup and quality.

The Abis Loop Test is carried out automatically by the BSC duringcommissioning. The test can also be carried out manually from the BSC.

4.7 BSS9062 BTS supervision

The Nokia Flexi EDGE Base Station monitors and tests itself during operationwithout a separate command.

Continuous monitoring

Both the software and hardware carry out monitoring. Most of the monitoringprocedures are so effective that no additional testing to find the faulty module isneeded. The following items are monitored continuously:

. Internal buses of the base station

. Transmission equipment and interfaces

. RF parts

. Mast head amplifiers

. Nokia Flexi Support and Nokia Flexi EDGE Base Station Battery Backup(MIBBU)

. Combining units (Remote Tune Combiner Module ECxA, Dual DuplexerModule ERxA and low-noise amplifiers LNA)

. Temperature (heating and cooling) system of the base station

. Power supply voltages

. Reference Oven Oscillator

If any of the supervision tests above fail, the alarm handling runs further tests.



Mains breakdown

A typical short voltage drop (that lasts less than 20 ms) does not cause anydetectable harm to the operation and does not cause an alarm. In case of a mainsbreakdown, the Nokia Flexi EDGE Base Station cannot send an alarm to the BSCwithout battery backup (either integrated or external).

4.8 BSS9061 Temperature control system

Nokia Flexi EDGE Base Station monitors its temperature continuously withseveral sensors located in several modules (System Module ESMA, Dual TRXModule EXxA, and Remote Tune Combiner Module ECxA). The BTS controlsits temperature with cooling fans to provide as stable operational conditions aspossible. Heating and cooling is controlled gradually depending on the ambienttemperature to ensure low temperature gradients and noise level.

If the temperature of a module rises too high, a temperature alarm is issued. If theSystem Module is overheated, the BCF is blocked. If the Dual TRX Module isoverheated, the associated TRXs are blocked. Power supply units have their owninternal shutdown and recovery in case they are overheated.

No separate heaters are required in Nokia Flexi EDGE BTS. In temperaturesbelow -10º C, the Dual TRX Module heats itself, and the other modules functionin the whole operational temperature range.

4.9 BSS9060 TRX Test

The total performance of the TRX is tested with a multi-purpose TRX Test. Thetest covers:

. Digital and RF parts

. RX operation and TX level

. Both RX branches

The TRX test time is approximately 15 seconds.

When the TRX test is carried out according to a regular schedule, it can be usedin TRX performance supervision.

Both RX branches are tested separately during the same TRX test. If diversity isnot configured, only the main branch is tested.



Operability

The TRX Test tests both the Tx and Rx RF paths of the selected TRX via anuplooped burst to the Air interface, including the Dual TRX module (EXxx) andDual Duplexer Module (ERxx) or Remote Tune Combiner Module (ECxx).

The power level during the TRX test is the same as the power level of thebroadcast control channel (BCCH). To avoid unwanted disturbances to the TRXs,the training sequence is not the same as the one normally used.

Figure 9. TRX Test window

You can test all TRXs in the BTS either remotely from the BSC or the NetAct orlocally with Nokia Flexi EDGE BTS Manager.

Note that the TRX test can be performed only in traffic channel (TCH) timeslots.Two free timeslots are needed for the test.

The TRX test is not possible when baseband hopping is used.



4.10 TRX Loop Test

Nokia Flexi EDGE BTS provides a TRX Loop Test facility. In a TRX loop test,data generated by SW in digital parts of the TRX is looped from the TX to RXside inside the Dual TRX module (EXxx) and the Dual Duplexer Module (ERxx)or the Remote Tune Combiner Module (ECxx), so that the TX- and RX-chainsexcluding antennas and antenna feeder cables are tested. Main or diversity pathscan be tested.

The BTS checks the looped test data, and the test result is given as BER values.

The TRX Loop Test can be performed with GMSK TCH/FS or 8PSK PDTCH/MCS-5 test channels.

4.11 BSS9059 Nokia BTS resets

You can reset the Nokia Flexi EDGE BTS objects and modules locally withNokia Flexi EDGE BTS Manager or objects remotely from the BSC or NetActvia Abis.

The reset types are as follows:

. You can reset the BCF, BTS and TRX separately from the BSC or fromNokia Flexi EDGE BTS Manager. A BCF reset means resetting all unitsexcept the Transmission sub-module (FIxA) - in practice, it is a site reset.

. The Transmission sub-modules (FIxA) will remain operational during aBCF reset, to ensure that the transmission cross-connections remainoperational.

. Each TRX within the Dual TRX Module (EXxA) is reset separately.

. You can reset the System Module (ESMA) and Dual TRX Module (EXxA)separately from Nokia Flexi EDGE BTS Manager.

. A System Module (ESMA) reset will reset all units including theTransmission sub-module (FIxA).

. A Dual TRX Module (EXxx) reset will reset the HW and SW for bothTRX objects within the Dual TRX Module (EXxA).



Operability

4.12 BSS9058 BTS fault recovery

BTS fault recovery minimises the effect of service level faults in the BTS. Faultdiagnostics ensures that an appropriate recovery action is carried out. The faultyobject is blocked before any recovery actions. After the recovery, the object isreleased. If the recovery does not succeed, a BTS alarm is issued.

For more information on fault recovery and BTS alarms, refer to TroubleManagement of Nokia Flexi EDGE BTS.

4.13 BSS9056 Autodetection of site configuration

Nokia Flexi EDGE Base Station detects the site configuration automatically,including all active modules and versions, their serial numbers and the frequencyband used. This information is stored in the in the flash memory of the SystemModule (ESMA), and it can be displayed in the Nokia Flexi EDGE BTSManager.

You need to set the operator-specific settings, such as external alarm line settings,from the BSC or the NetAct, for example with the Remote MML session.

A possible change in any of the modules or in the configuration causes anautomatic system data update in the flash memory of the System Module. Theconfiguration is detected both in normal start-up situations and when extracapacity (more TRXs) is added, modules are removed, or a faulty module isreplaced with a new one.

The transmission configuration is also backup-copied to the System Module.

4.14 BSS9003 Power system management for SiteSupport/IBBU (from Nokia NetAct)

Power System Management (PSM) is a remote management system for theIntegrated Battery Backup Units (IBBUs) and the Site Support (SiSu), whichremoves the need for a site visit for the simple power system related tasks.

The solution utilises the internal Q1 bus for remote control and the datatransmission between NetAct-BSC-BTS-IBBU/SISU.



Figure 10. Power System Management for the Site Support/IBBU (from NokiaNetAct)

Tests

Alarms

Power Control

Battery Details

IBBU/SiSuConfiguration

BSC NetAct

IBBU/SiSu BTS

Q1

PSMQ1



Operability

5 Site solutions

5.1 BSS10046 Multi BCF Control

Multi BCF Control allows the combination of several BTSs into one logical cell,enabling you to increase the capacity of a cell while maintaining the maximumspectral efficiency. Multi BCF Control increases the cell capacity for Nokia FlexiEDGE BTSs to 36 TRXs while requiring no extra BCCH. Multi BCF alsoprovides a path for site expansion from Nokia UltraSite EDGE BTS to NokiaFlexi EDGE BTS.

Multi BCF Control requires that BSS9055 Clock Synchronisation between basestations, or BSS10069 Synchronised BSS is used.

You can arrange base stations so that the TRXs in different base stations(operating on the same frequency band) can serve the same cell with a singleBCCH. At the base station site, you need to make some installations, for examplesynchronisation is needed between the base stations. All the base stations willhave a separate O&M link to the BSC. At the BSC, you need to use a SEGMENT(SEG) object to set all the BTS objects sharing the same BCCH.

Figure 11. Multi BCF configuration

Multi BCF cell (= SEG)

f1 f2 f3

f4 f5

UltraSite TRX group

Flexi TRX group



Site solutions

5.2 BSS9055 Clock Synchronisation between BaseStations

The Clock Synchronisation between Base Stations enables synchronoushandovers between base stations. The sectors defined to different base stationscan use common hopping frequencies with RF hopping, which increases thechannel capacity. The maximum site configuration is

. 9 Nokia Flexi EDGE BTSs in a chain or

. 1 Nokia UltraSite EDGE BTS + 5 Nokia Flexi EDGE BTSs.

The Nokia Flexi EDGE Base Station has an external clock interface that can beused to synchronise the air interface between several Nokia Flexi EDGE BaseStations located on one site.

When several Nokia Flexi EDGE Base Stations are synchronised, the master basestation (master BTS) functions as the frame clock source to the slave BTSs. Themaster BTS transmits the frame clock and frame number signals to the externalclock line, while the other BTSs (slave BTSs) receive these signals. The slaveBTS uses the received frame clock signal as a reference clock signal to adjust itsmain frequency source. The master BTS uses the reference clock signal derivedfrom the Pulse Code Modulation (PCM) signal.

After modifications to the Nokia UltraSite EDGE BTS, it is possible tosynchronise a Nokia Flexi EDGE Base Station to a Nokia UltraSite EDGE BTSto serve the adjacent sectors. In this case the clock master is always a NokiaUltraSite EDGE BTS because there is a permanent timing difference between theNokia Flexi EDGE Base Station and the Nokia UltraSite EDGE BTS. Only theNokia Flexi EDGE Base Station can compensate the timing difference bydelaying the internal timing.

Physical properties

The maximum cable length for the total system is 100 metres. Thesynchronisation chain between the BTSs is made using RS-485 connection forthe transferred clock signals.

Synchronisation recovery

If there is a failure in the synchronisation between the base stations, the slaveBTS generates an alarm and the BSC then blocks all TRXs of the alarming BCF.When the fault disappears, cancellation to the alarm is sent to the BSC. The BSCthen unblocks the TRXs under the alarming BCF object.



Fast tuning

. If the clock reference is taken from Abis:

If the BTS is being commissioned, the fast oven-controlled crystal oscillator(OCXO) tuning is executed for the maximum duration of 8.6 seconds. The targetaccuracy is 0.02 ppm. The adjustments can be 10 times larger than in normaltuning. After fast tuning, the BTS starts normal tuning, and allows the BTSconfiguration to be completed.

. If the clock reference is taken from an external synchronisation source(other BTS or LMU):

If the BTS is being commissioned, the fast OCXO tuning is executed for anindefinite duration until the target accuracy of 0.02 ppm is met. Typically, theexternal clock reference is stable, therefore the fast tuning is completed in 4.6seconds (two rounds). The first round is for getting the reading and foradjustments, and the second round is for validating that the required accuracy ismet. The adjustments can be much larger than in normal tuning. After fast tuning,the BTS starts normal tuning, and allows the BTS configuration to be completed.

Normal tuning

With Abis as reference, the digital-to-analogue converter (DAC) word adjustmentmay occur every 20 minutes. The purity of Abis is monitored continuously, andthe adjustment is only performed if the purity is good enough.

With an external clock as reference, the DAC word adjustment may occur every20 minutes. The presence of the external clock source is monitored, the purity isnot. When the external clock is present, the adjustment is made.

With both clock sources, the current DAC word is written as a new calibratedDAC word, if the current DAC word eventually drifts far enough from thecalibrated DAC word. This ensures that in later start-ups (in any environmentalconditions), the BTS starts immediately with as an accurate value as possible, andthe C-plane and U-plane signalling and traffic remain undisturbed.

Note

Do not manipulate the calibrated DAC word with Nokia Flexi EDGE BTSManager, because the best possible calibrated DAC value is already providedin production. Because of actual circumferential conditions (the externalsynchronisation or Abis can be less accurate), the DAC word tuning isenforced to follow those sources, and on reference signal purity, the DACword tuning can either be performed or not.



Site solutions

5.3 BSS10069 Synchronised BSS

With Synchronised BSS, all the clocks of the different sites in the network aresynchronised, so that the GSM frame timing is aligned between all sites.

This is done by using a Location Masurement Unit (LMU), which gets a GPStime reference, and uses this to generate a clock signals for the BTSs.

Synchronising all BTS sites in the network decreases overlapping of the TDMAbursts and thus minimises interference and the frame error rate (FER). Highertolerance to interference leads to better performance and makes frequency reuseas well as the cell re-selection and handover processes more effective. It alsogives more accuracy for the MS locationing functionality.

5.3.1 BSS20371 BSS Site Synchronisation Recovery Improvement

BSS Site Synchronisation Recovery Improvement is an improvement toBSS11073 Recovery for BSS and Site Synchronisation. With BSSSynchronisation Recovery Improvement, the BTS site continues in the BSSsynchronised service even if the GPS coverage is lost for up to 24 hours. TheBTS site also continues in the BSS synchronised service throughout an LMUsoftware update.

Requirements

The transmission link(s) to the BTS site must meet the Jitter and Wanderrequirements of ANSI T1.403 for T1 links, or ITU G.823 for E1 / 2048 kbit/sechierarchy links.

Apart from the O&M element, no changes are required in other BTS softwareelements (Telecom and DSP). No new requirements are identified for the NokiaFlexi EDGE BTS Manager.

The following BTS generations and software support Recovery for BSS and SiteSynchronisation:

. Flexi EDGE BTS EP1

. UltraSite EDGE CX4.1

. BSC S11.5

. LMU 4.3




Improved BSS Synchronisation Recovery is used in any networks which use BSSSynchronisation with or without DFCA.

5.3.2 BSS11073 Recovery for BSS and Site Synchronisation

The main purpose of Recovery for BSS and Site Synchronisation is to giveautomatic recovery for BSS Synchronised sites (sites with LMU) if the BSS20371 Site Synchronisation recovery improvement is not used.

. when the Location Measurement Unit (LMU) clock signal is lost, to get thechained BTS cabinet (site) into an unsynchronised mode

. when the LMU clock signal is again available, to return the chained cabinetback into a synchronised mode

Recovery for BSS and Site Synchronisation also offers synchronisation recoveryfor a Multi BCF site using BSS9055 Clock Synchronisation.

When the BTS chain is defined in the BSS radio network database, Recovery forBSS and Site Synchronisation automates the recovery if the BTSs in the chain aresynchronised and the clock signal is lost and regained. On the other hand, if thechain is not defined or the BSS or Site synchronisation of the chain has not beenactivated, you need to lock and unlock the sites in the correct order to enablesystem synchronisation. The BSC receives the information for recovery from Q1and BTS alarms.

Recovery for BSS and Site Synchronisation can be used together with theDynamic Frequency and Channel Allocation (DFCA) when the LMU is definedas a clock source in the BSS radio network database and the BCF is in asynchronised mode, and with the Multi BCF configuration, provided that all theunlocked BCFs are defined to the same chain operating in a synchronised mode.

For a Flexi EDGE BTS chain, the maximum number of BTSs is nine.



Site solutions

Figure 12. Synchronised BSS example in Flexi EDGE BTS chain

The BSS is synchronised by a Global Positioning System (GPS), that is, LMUsare installed to every site with GPS antennas. The clock source is a GPS satellitevia the LMU. When the LMU feeds the clock, all BTSs are working as slaves.When the LMU clock feed is lost, the BSC starts a timer. The synchronisedoperation continues uninterrupted based on the BTS internal clock. If the BSCtimer expires, the first BTS in the chain becomes a clock master and startssupplying the clock signal to the other BTSs. The BTS synchronisation statusindication in the BSC is changed to 'unsynchronised'. When the LMU clock isrecovered, the BTS becomes synchronised again.

Recovery for BSS and Site Synchronisation supports the following BTSgenerations and SW, when the chain is defined:

. Flexi EDGE BTS with EP1

. UltraSite EDGE BTS with CX4

. When BSS synchronisation configuration is used, LMU SW 4.3 or LMUBSW 1.0 is required with the feature

Benefits

Automatic recovery for the loss of LMU clock, when the BTS chain is defined inthe BSS radio network database:

BSC

LMU(master)

BTS(Flexi)(slave)

IN OUT

Abis

FN Offset

Q1

FN, FCLK

BTS2(Flexi)(slave)

IN OUT

BTS3(Flexi)(slave)

IN OUT

FN, FCLK FN, FCLK



. Automatic BSC-controlled recovery to unsynchronised operation

. Automatic BSC-controlled return to synchronised operation

. Timeslot offset parameter sending to LMU

. BTS synchronisation configuration and mode information available fromthe BSC by MML and NetAct

5.4 Operating bands

Nokia Flexi EDGE BTS supports the following operating bands:

. GSM 800

. GSM 900 (including E-GSM and P-GSM)

. GSM 1800

. GSM 1900

Dual and Tri Band Common BCCH

Common BCCH allows the combination of two or more sectors into a singlelogical cell, with a single BCCH carrier. With common BCCH sectors in differentfrequency bands such as 900/1800 MHz (or 800/1900 MHz, or 800/1800 MHz)can be configured with a common BCCH carrier.

The main advantages of the common BCCH functionality are:

. Improved trunking gain

. Use of signalling channels is optimised by sharing them between bands

. Tighter reuse of all carriers in the non-BCCH bands

. Better call quality because of decreased number of handovers

To ensure proper operation of the network, take into account issues related to thedifference of propagation between the different bands when performing cellplanning.



Site solutions

Figure 13. Common BCCH configuration

Frequency hopping between bands in the same sector is not supported.

5.5 BTS2043 BTS External Alarms and Controls (EAC)

External Alarms and Controls (EAC) signals can be defined to the BTS.

Benefits

The external alarms and controls allow alarms to be sent from external equipmentattached to the BTS, and allow control of external equipment attached to the BTS.

External Alarms caused on the site, such as the intruder alarm, are sent to theNetAct via the Abis. The alarms are TTL level signals, all referred to 5 V. Youcan define whether an alarm is raised when the alarm input line is grounded ordisconnected from the ground potential (this is known as alarm polarity). Thisallows more flexibility for the alarming device.

The External Controls allow the user to control external equipment remotely fromthe BSC. The External Controls are of open-collector type.

The EAC settings (such as name, alarm polarity, control state) are defined at theBSC. You can view the EAC names at the BSC.

Restrictions

There are 24 user-definable external alarms and 6 user-definable externalcontrols. The System Module (ESMA) provides 12 alarm inputs and 6 controloutputs. Another 12 alarm inputs are available with the optional Flexi SystemExternal Alarm Module (FSEA).

Common BCCH cell

f1 f2 f3

f6 f7 f8

f4 f5

PGSM 900 TRX group

EGSM 900 TRX group

GSM 1800 TRX group



5.6 BTS2020 RX antenna diversity

Receiver diversity (spatial diversity) is available as an operation SW for allconfigurations. The two RF signals are demodulated separately and combined bythe post detection weighted summing method.

Diversity is defined for every sector separately from the BSC.



Site solutions

6 Basic GSM operation

6.1 Basic GSM features

Nokia Flexi EDGE BTS supports the following basic GSM features:

. Full rate speech codec

. Half rate speech codec

. Circuit Switched Data Services to 14.4 kbps

6.2 BSS6071 Enhanced Full Rate Codec

Enhanced Full Rate Codec (EFR) uses the existing GSM 900/1800 full ratechannel coding but provides a considerably better performance in all channelconditions. Moreover, in good channel conditions, the codec ensures equal oreven better quality than Adaptive Differential Pulse Code Modulation (ADPCM).

Transcoder Sub-Multiplexer 2 (TCSM2) SW can be upgraded for the EFR.

As for the Air-interface dimensioning, no special attention to the EFR channelsneeds to be paid. The A-interface and transcoders must be dimensioned accordingto each pool type.

The EFR can coexist with Half Rate (HR) or Full Rate (FR) 'dual codec'.

The mobile switching centre (MSC) provides basic information on the codectype. If no information about the codec types supported on circuit group basisover the A-interface is available at the MSC, all A-interface channels must beequipped with the TCMS2.

The base station controller (BSC) decides the codec type based on:



Basic GSM operation

. the input from the MSC

. the BSS speech codec capabilities

. radio channel configurations and their availability (FR/HR)

During handovers, the BSC may change the speech codec. For intra-BSChandovers, the BSC uses the previously stored information from the MSC/VLR(visitor location register) on the speech codec preferences.

The BSC forwards the information on the codec type to the base transceiverstation (BTS) in the channel activation message. The BTS configures the activetimeslot according to this information to support either the conventional full ratecodec or the EFR. In-band signalling between the transcoder and the BTS is usedto control the transcoder codec selection on a call basis.

6.3 BSS6025 Short Message Service Cell Broadcastwith Discontinuous Receiving (SMS-CB DRX)

SMS-CB DRX enables phase-2 Mobile Stations (MSs) to receive only the neededblocks of the CBCH (Cell Broadcast Channel). This decreases batteryconsumption.

The BSC has a user interface for SMS-CB (Short Message Services CellBroadcast) and it stores CB messages in the BSS. After the BTS initialisation, theBTS operates in non-DRX (Discontinuous Receiving) mode until SMS-CB DRXis activated in the BSC. When SMS-CB DRX is employed, the BTS startstransmitting Schedule Messages to the cell area. A Schedule Message includesinformation about a number of immediately following consecutive CB messages,planned for that cell. The time between two Schedule Messages is called theSchedule Period. The Schedule Period is one minute (see the figure below).

The MS starts operating in DRX mode after the power up when it has receivedthe first Schedule Message. If the MS does not receive a Schedule Message, it hasto read at least the first block of each CB message.

Figure 14. SMS-CB DRX Schedule Period

SchCB1

CB2

CB31

Sch Sch

60 s

.... ....

CB1



In DRX mode, in the first block of the Schedule Message, the MS receivesinformation about

. How many CB messages there are

. In which slot they will be transmitted

. Message identifiers (if there are fewer than 6 new messages)

If there are:

. No new CB messages in successive schedule periods, the MS ends upreading only the first block in each Schedule Message.

. 1 to 5 new CB messages, the MS does not need to read other blocks in theSchedule Message, but it still needs to read the new CB messages.

. More than 5 new CB messages, the MS has to read more than one block inthe Schedule Message plus all the new CB messages.

6.4 BTS2503 Compressed Abis timeslot allocation

In traditional transmission solutions, some capacity is left unused, especially inthe case of BTSs with one TRX, because one radio interface time slot is alwaysused for the BCCH. The compressed Abis time slot allocation makes it possibleto use this capacity for TRX signalling. It is also possible to use another 16 kbit/sslot to carry the O & M signalling required for the site. This slot can 'steal' theTCH transmission slot thus leaving capacity for six full rate TCHs or twelve halfrate TCHs for that TRX.

In environments where it is not necessary to use the full traffic capacity of a TRX,compressed Abis time slot allocation offers an ideal solution for using thetransmission medium more efficiently. With this configuration, it is possible to fit15 TRXs to one 2 Mbit/s PCM.

6.5 BTS2133 Short Message Service (SMS) point-to-point

Nokia Base Station supports the short message service (point-to-point) for bothmobile originating and mobile terminating calls.



Basic GSM operation

6.6 BTS2067 Fast Associated Control Channel(FACCH) Call Setup

With Fast Associated Control Channel (FACCH) Call Setup, it is possible toestablish a call without using a stand-alone dedicated control channel (SDCCH).A traffic channel (TCH) is set to 'signalling only' and switched over to normalspeech operation when needed. FACCH Call Setup is for emergency calls only.

6.7 BTS2037 Air interface measurement pre-processing

The measurement results for the active channels may be averaged for the TRX.This option is useful when 16 kbit/s signalling is used because it reduces thecapacity needed on the Abis link. The averaging period may be set to consist of 1- 4 SACCH multiframes. Both uplink and downlink measurements are averaged.As a result, the BSC receives a measurement report once at the end of theaveraging period rather than after every SACCH multiframe.

6.8 BTS2033 Short message cell broadcast

The short message service (cell broadcast) defined in the GSM recommendationsis supported.

6.9 BTS2024 Synthesised frequency hopping

Synthesised frequency hopping is available for configurations that have at leasttwo TRXs per sector. Synthesised frequency hopping enables all TRXs to changefrequencies in successive timeslots, so that the carriers can hop at many differentfrequencies in quick succession. Both random and cyclic hopping can be used.The maximum number of frequencies per BTS site is 64. The number offrequencies can be greater than the number of TRXs.

Note that the BCCH carrier must remain at a fixed frequency and at a fixed powerlevel to enable the MS to measure the signal strength.



6.10 BTS2023 Downlink and uplink DTX; TCH/FS,speech

The DTX function (discontinuous transmission activated by speech) is supportedas specified in the relevant GSM recommendations.

6.11 BTS2013 Baseband Frequency Hopping

Gigabit Ethernet is used to cross-connect the baseband part and the Dual TRXModules (EXxA) through an L2 switch to facilitate baseband hopping. The cross-connection is done on a 'per timeslot' basis. Both random and cyclic hopping canbe used.

Baseband hopping is allowed for all BTS configurations. The number offrequencies used in the frequency hopping sequence is the same as the number ofTRXs in the sector.

6.12 BTS2012 BTS time base reference from PCM

The PCM clock is used as a reference when tuning the long-term accuracy of theBTS internal clock. The requirement for the accuracy is 0.015 ppm in order tomeet the GSM requirement (0.05 ppm) for the clock signal accuracy in the Airinterface.

6.13 BSS7036 Dynamic SDCCH Allocation

Dynamic Stand-alone Dedicated Control Channel (SDCCH) Allocation allowsthe SDCCH resources to be configured according to the actual SDCCH trafficsituation of a cell. When the BTS temporarily needs greater SDCCH capacitythan normal, the BSC configures the idle traffic channel (TCH) resources forSDCCH use. For an example of this, see the figure below. A maximum of twoadditional SDCCH/8 can be configured. When the SDCCH congestion situationis over, the extra SDCCH resources are configured back to TCH resources.Dynamic SDCCH Allocation can be used with both combined and non-combinedBroadcast Control Channel (BCCH).

You only need to configure the BTS to the minimum static SDCCH capacitysufficient to handle the normal SDCCH traffic.



Basic GSM operation

Figure 15. Dynamic SDCCH allocation

Extra SDCCH resource is allocated only when the existing SDCCH is fullyloaded. When the dynamic SDCCH radio resource is totally free again, it isimmediately reconfigured for TCH use. Thus, the maximum number of TCHs isalways in use depending on the actual need of the SDCCH resources at eachmoment.

Dynamic SDCCH Allocation benefits traffic cases in which signalling is the onlytransmission to the network, for example Short Message Service (SMS) trafficand location updates. In some special places, such as airports and stations, thelocation updates can produce sudden short-term SDCCH congestion. WithDynamic SDCCH Allocation, this can be handled without any need to configureextra permanent SDCCH capacity.

TCH(busy)

TCH TCH(busy)

TCH(busy)

SDCCH/8

BCCH SDCCH/8 TCH(busy)

TCH(busy)

TCH(busy)

TCH(IDLE)

TCH(busy)

TCH

TRXwith staticSDCCH/8

New TRXconfiguration

with additionalSDCCH/8

SDCCH congestion triggersdynamic allocation of SDCCH for free FR RTSL

BCCH SDCCH/8 TCH(busy)

TCH(busy)



7 Transmission

7.1 Basic transmission

7.1.1 Abis Trunk Transmission for E1 (ETSI) interface

Up to four full rate (FR) or Enhanced Full Rate (EFR) speech channels, or up toeight Half Rate (HR) speech channels, are multiplexed on a single PCM timeslot.It is possible to create point-to-point star, multidrop chain or remote startransmission connections between BSC and BTS sites. This flexibility ensuresthat all kinds of transmission needs are fulfilled: traditional star configuration,economical multidrop chains, and reliable multidrop loops are all possible.

Up to 12 TRXs are supported on a single 2 Mbit/s PCM line. Accepting that oneor two speech channels are lost, up to 15 TRXs can be supported.

Abis Trunk Transmission Allocation is implemented using the standard G.703 2Mbit/s PCM frame structure.

For more information, see Nokia BSS Transmission Configuration in BSC/TCSM Product Documentation.

7.1.2 Abis Trunk Transmission Allocation for T1 (ANSI) Interface

Up to four full rate/enhanced full rate (FR/EFR), and eight with Half Rate (HR)speech channels are multiplexed on a single PCM timeslot. It is possible to createpoint-to-point star, multidrop chain or remote star transmission connectionsbetween BSC and BTS sites. With this flexibility, all kinds of transmission needscan be satisfied: traditional star configuration, economical multidrop chains, andreliable multidrop loops are all possible.

Up to 10 TRXs are supported on a single 1.5 Mbit/s PCM line. Accepting thatone or two speech channels are lost, up to 12 TRXs can be supported. Thisfeature is implemented using the standard T1.403 PCM frame structure.



Transmission

The T1 TRU supports Extended Super Frame (ESF) and SF/D4 framing. ESFsupports CRC-6 checks and 4 kbit/s datalink for performance management

7.1.3 Abis Trunk Signalling

Radio Signalling Link is a logical link between the BSC and the BTS in Layer 2.The RSL is identified by a functional address known as Service Access Point,SAPI=0. Radio signalling links over the Abis interface are addressed to differentunits by Terminal Endpoint Identifiers, TEI. The TEI values are fixed andcorrespond to the TRX-id. The TEI management is not used.

One signalling channel is used for each transceiver (TRX) and one for each BTSbase control function (BCF). Alternative signalling speeds are available: 16 kbit/s, 32 kbit/s, or 64 kbit/s. The selection of the signalling speed is done in thecommissioning phase on BTS basis. The same selection is also done on the BSCsite when channel configuration is defined.

Normally, 16 kbit/s TRX signalling speed is recommended for the FR operation.32 kbit/s TRX signalling rate is recommended for the HR use.

At the BCF signalling rate of 64 kbit/s, the SW downloading time needed isapproximately four times shorter than with 16 kbit/s signalling.

7.1.4 Network Synchronisation

In normal network conditions, synchronisation information is carried by selected2 Mbit paths from upper to lower hierarchical levels according to thesynchronisation plan, from the MSC down to the BTSs.

Nokia Flexi EDGE BTS selects the 2 Mbit signal that has the highest priorityfrom a group of pre-selected digital paths as the active synchronisation signal.You can change the group of signals using the Nokia Flexi EDGE BTS Managerapplication. Selection of a new signal is automatic in case of input failure andinput recovery.

In addition to using 2 Mbit signals for synchronisation, you can choose tosynchronise with an external clock signal, such as the LMU clock signal.

Network Synchronisation can be protected via PDH Loop Protection. See Abisloop protection for more details.



7.1.5 Support for Nokia Microwave Radio Links

The FlexBus transmission sub-module (FIFA) forms the integrated microwaveunit support with Nokia Flexi EDGE BTS.

One FIFA transmission sub-module is used per Nokia Flexi EDGE BTS with twoFlexBus interfaces, allowing for microwave radio tail and chain site topologiesusing Nokia FlexiHopper and MetroHopper.

The FIFA sub-module offers E1 bypass cross-connections from one FlexBusinterface to the other, and up to 16 x E1 add/drop capability to Nokia Flexi EDGEBTS and sub 2M cross-connect function.

The FIFA sub-module is visible as a separate managed element at Nokia NetAct.You can manage the FIFA sub-module locally and remotely using NokiaFlexiHub manager. Nokia Flexi EDGE BTS provides functions for alarm,performance data polling and forwarding to the BSC.

7.1.6 BSS9065 Transmission Operability

Nokia Flexi transmission equipment is measured with several counters asfollows:

. All equipment can be measured within 15min/24-hour periods. Thismeasurement gives a fixed set of counters, which are near-end G.826signal quality counters. These counters are:. Total time. Available time. Errored seconds. Severely errored seconds. Background block errors. Errored block

. A certain set of Nokia Flexi transmission equipment can be defined. NokiaFlexi transmission equipment refers either to the whole equipment or partof it (functional entity and supervision block). It is also possible to definethe counters that are collected from the equipment. To do this, you need toknow the topology of the transmission network so that the measurementsubject can be chosen.



Transmission

7.2 Transmission solutions

7.2.1 Q1 Interface Between the BSC and Transmission Equipment

The Nokia Flexi EDGE Base Station supervises the transmission equipment thatcan be either internal or external. External transmission equipment is Q1compatible, has its own power supply and is controlled from the interface unit viaQ1 connection. The alarms generated by the transmission units are transmitted tothe BSC that further transfers them to the NetAct.

With the Q1 Interface Handling MML, the user creates the service channels usedin communication between the BSC and the transmission equipment. The Q1service channels are asynchronous serial communications channels. The protocolused is Nokia's own Transmission Management System Protocols.

The default maximum number of Q1 service channels in the BSC is 18.

The user also defines the supervised equipment. Altogether 512 pieces ofequipment can be defined into Q1 service channels under the BSC. All theequipment in the same channel has a unique address (polling address).

To succesfully access the equipment assigned to the service channels, theequipment must be configured with its Q1 address locally, with a hand-heldservice terminal or the equipment's manager application.

Supervision of transmission units supplied by other manufacturers

When transmission units supplied by other manufacturers are supervised viaExternal Alarm and Control (EAC) lines, the alarms can be sent to the BSC andNetAct. When the alarms are sent to the BSC and NetAct, the System Module(ESMA) supervises the alarm handling and alarms are reported as normalexternal alarms.

7.2.2 PDH traffic routing

Cross-connections define how signals are routed from a transmission interface toanother transmission interface. They are the basic building blocks for creating thepath for transmitting the Abis capacity from the Nokia BSC to the Nokia BTS viainterconnecting nodes.



Cross-connection granularities

There are several types of cross-connections available, and each has a differentgranularity. Granularity means the bit rate at which a cross-connection is made,that is, the number of bits connected into a specific direction in a cross-connection. In 2 Mbit/s mode, the available granularities are:

. 8k (1 bit)

. 16k (2 bits)

. 32k (4 bits)

. 64k (all 8 bits in a time slot)

. n x 64k

Grooming

The cross-connection feature of the transmission units makes traffic groomingpossible.

Nokia Flexi EDGE BTS is capable of grooming traffic at for example 8 kbit/sgranularity, which enables fully optimised and flexible use of the availabletransmission resources. This ensures that the path used for transmitting Abiscapacity can be used efficiently.

7.2.3 Abis loop protection

Nokia PDH loop protection is considered an efficient way to protect traffic in atransmission network such as a base station subsystem (BSS). In a livetelecommunications network it is important to secure, in addition to the actualpayload traffic, the network synchronisation and the centralised networkmanagement during any period of abnormal circumstances.

For these reasons, Nokia PDH loop protection protects:

. payload traffic

. network synchronisation

. network management connections

A transmission loop formed with Nokia elements consists of a loop master andone or more loop slaves. Usually the loop master is a transmission node, whereasthe loop slaves can be either transmission nodes, BTSs or a combination of bothinside one loop.



Transmission

The loop principle is that the transmitted signal is always sent in both directions,but the received signal is selected from one direction only. The loop master sendspilot bits on the basis of which the switching decision is made. Each individuallyprotected slave station needs one pilot bit.

Network synchronisation must also be ensured in a loop network and it followsthe loop principle in a similar way. The synchronisation switching takes placeindependently from the pilot bits by having master clock bit (MCB) and loopcontrol bit (LCB).

Based on the configured priorities, each network element decides individuallyfrom which direction the signal and the synchronisation will be received, and,thus, it does not require any external or additional supervision for its decision.

Figure 16. Loop principle

Nokia's way of implementing loop protection is ultimately secure, providing veryfast route switching that recovers the transmission connections instantly. Nokialoop protection is embedded and thus very fast. Nokia loop protection protectsagainst failures, such as cable-cuts, equipment failures, heavy rain and multipathfading, and against obstacles in the line-of-sight, such as cranes and growingtrees.

Loopmaster

= Loop slave

Normal receive direction

Reverse receive direction

Pilot bitsPilot bits

Direction 1Direction 2

Transmissionnetwork



Compared to an unprotected wireless network, Nokia PDH loop protectionincreases site availability at least tenfold and prevents end-of-chain availabilitydegradation.

The protection functionality is compatible with the existing Nokia BSStransmission.

Nokia Flexi EDGE BTS can only act as a slave node in a Nokia PDH Loopprotected network.

For more information refer to the Nokia PDH Loop Protection in GSM Networksdocument that can be obtained upon request.

7.2.4 Redundant Abis Trunk

If a failure or a problem in the transmission connection occurs between BSC andBTS sites, an alternative transmission route (redundancy) is desirable.

Two alternative strategies are available for redundancy:

. a duplicated point-to-point type connection

. a redundant multi-drop loop connection

These two alternatives provide solutions for different transmission needs: eitherthe traditional redundant point-to-point configuration or the economicalmultidrop loop configuration.

Redundant Abis Trunk for E1 interface (ETSI) is implemented by using thestandard G.703 2 Mbit/s PCM frame structure.

Redundant Abis Trunk for T1 interface (ANSI) is implemented by using thestandard T1.403 1.5 Mbit/s PCM frame structure.

For more information, see Nokia BSS Transmission Configuration in BSC/TCSM Product Documentation.



Transmission

Appendix A Other features

A.1 Other features

Nokia Flexi EDGE BTS also supports the following feature enhancements madein Nokia UltraSite EDGE BTS:

. Enhanced Automatic Frequency Correction (E-AFC)

. BSS10022 Frame Erasure Rate (FER) Measurement

. BSS9064 Real Time Update to BTS

. BSS7068 CCCH Improvements

. BSS6074 Active Channel Interference Estimation

. BSS5072 Better Random Access Channel Detection

. BTS2041 BTS Local Blocking



Other features

Nokia Flexi EDGE BTS Feature Descriptions

Documents

Transcript of Nokia Flexi EDGE BTS Feature Descriptions