ZTE UMTS Indoor Coverage Solution 201001V1.0

ZTE UMTS Indoor Coverage Solution

Importance of 3G Indoor Coverage

ZTE Indoor Coverage Solution - MRRU

Applications of ZTE Indoor Coverage Solution




Contents

Network QoS: Lifeline for Operators

Customer Satisfactory Degree

Network QoS

Coverage Rate

Access

RateCall Drop

RateVoice Quality

Data Service Success Rate

Data Service Bandwidth

NodeBNumber

NetworkSupport

Customer Perception

KPIs Network propagation

Public

Praise Propagation

Network QoS is the lifeline for operators!Network QoS is the lifeline for operators!

4

Indoor Data Services: Key to Raise Income for 3G Operators

Based on the statistics of DoCoMo, proportion of 3G indoor

services reaches 70% of the total, and most are new services

offered by 3G network.

Data service can help to enhance the ARPU of subscribers,

which can complement the ARPU decreasing of voice services.

Data service becomes the key driving force for the operators to

conduct the diversified services and to improve the ARPU.

0

5

10

15

20

25

30

35

40

45

50

1998 1999 2000 2001 2002 2003 2004 2006 2008

Total ARPU Voi ce ARPU Data ARPU

European mobile market income statistics ($ 1 billion)

Source: Yankee Group

NTT DoCoMo has accelerated

the construction of indoor

coverage since 2004. Till 2006,

the proportion of indoor base

stations has reached 23% of the

total. And, this proportion keeps

increasing.

Taking the first phase of the UMTS commercial network of

China Unicom as an example, the base stations for indoor

coverage accounts for 1/3 of the total.

With the construction of the network, the number of base

stations for indoor coverage keeps increasing, and may account for

2/3 of the total.

Meanwhile, with the increasing of network subscribers, the

proportion of cells for indoor coverage would also increase.

5

Good Indoor Coverage: Crucial for Constructing Excellent 3G Network

The high frequency feature of 3G brings high space loss; in

addition, the excessive high penetration loss makes it hard for

outdoor macro base stations to bring sufficient radio coverage for

indoors.

Most services (both voice and data) occur indoors. Thus, a

good indoor coverage would help to improve the network capacity.

For 2G network, most services are voice

services. The simple wide coverage

strategy is used to satisfy the coverage and

capacity requirements.

CoverageCoverage

CapacityCapacity

CoverageCoverage

Capacity

Capacity Qua

lity

Qua

lity

2G

3G

We can see from aspects of coverage, capacity, and network quality that good indoor coverage is We can see from aspects of coverage, capacity, and network quality that good indoor coverage is

crucial for constructing excellent 3G network.crucial for constructing excellent 3G network.

We can see from aspects of coverage, capacity, and network quality that good indoor coverage is We can see from aspects of coverage, capacity, and network quality that good indoor coverage is

crucial for constructing excellent 3G network.crucial for constructing excellent 3G network.

Diversified 3G Indoor Coverage Scenarios

6

Indoor areas have enclosed radio environment. The coverage in these areas

must be coordinated with the large network.

MuseumAirport

Stadium

Multiple indoor coverage scenarios exist, and most are important scenarios like hotels and office buildings. A great amount of VIP subscribers are concentrated in these areas.

Multiple indoor coverage scenarios exist, and most are important scenarios like hotels and office buildings. A great amount of VIP subscribers are concentrated in these areas.

Hotel

SubwayTunnel

Parking lot

Office building

Residential building

Diversified scenarios, large

amounts of subscribers, and

heavy load of data service

Indoor coverage is crucial!

Since 80% of the business of the VIP subscribers happen indoors, the returns of indoor services is

high.

Strengthen the indoor coverage construction

and enhance the brand advantage.

Current Problems of 3G Indoor Coverage

Insufficient number of

indoor distribution systems

Low quality of

indoor coverage

Insufficient indoor

coverage capacity

Slow to locate

indoor coverage problems

In addition to the reconstruction of original 2G system, some new

sites can be added for some high-value buildings which are not

covered by the 3G network yet.

Large amount of active devices exist. The failure rate of these devices is high and there is no monitoring for them. The engineering quality still needs to be improved, and the intra-frequency interference at high levels of the buildings are severe.

The repeater will provide no capacity, and leakage of indoor

signals would affect the capacity of the large network. In

addition, the capacity expansion of the indoor network is

insufficient.

The engineers may lack sufficient knowledge about the 3G

network, which slows down the troubleshooting. In addition, it is

hard to perform effective optimization speedily.

Poor sustainable

optimization capability

For lack of sustainable optimization capability, we cannot

optimize the network in real-time with the developing of the

network.

Accelerate indoor coverage construction, improve the brand advantage, and surpass the competitors.

Accelerate indoor coverage construction, improve the brand advantage, and surpass the competitors.

Focuses of Indoor Coverage Optimization

Simplify capacity expansion

Reduce O&M costReduce engineering difficulty

Construct model UMTS

network

Improve user perception

Indoor distribution

system optimization

Indoor distribution

system optimization

Target: Optimize coverage, capacity, and engineering quality. Target: Optimize coverage, capacity, and engineering quality.

9

Indoor Coverage Optimization Technique Analysis

Improvement of indoor coverage quality depends on system-level

parameters upgrade and indoor and outdoor systems optimization.

Improvement of indoor coverage quality depends on system-level

parameters upgrade and indoor and outdoor systems optimization.

There are signals, but incoming or outcoming calls fail.

Call drop Poor Ec/Io

Weak coverage

Reselection problem

Handover problem

Terminal problem

No network

Customer Perception Problem

Antenna reconstruction

Frequency optimization

PSC optimization

Parameter optimization

Terminal upgrade

Solution

Slow network speed

Analysis and Solution of Indoor Coverage Problems

The indoor distribution system vendor

may have insufficient knowledge about

the system. Then, they fail to provide a

unified planning and optimization for both

indoor and outdoor systems, which may

lead to the indoor user perception

reduction.

Solu

tion

The system equipment vendor should take a leading role in the indoor coverage optimization. The system equipment vendors have deep understanding of the system topology and equipment performance, and they are equipped with rich network planning & design & optimization experiences. Thus, they can provide unified planning & optimization for indoor and outdoor systems.







Contents

12

Traditional 2G Indoor Coverage Solutions

Traditional indoor coverage solution: The network is mainly composed of micro-cell and

macro base stations. Lots of active systems are used.

The signal source is usually provided by macro base stations and cellular network. The macro base

stations are usually used in the indoor distribution system, then signals provided by these base stations can

cover indoor service requirements. The micro-cell is usually used in hotspots.

For a distribution system, the passive, active and leaky cable distribution systems can be used. The

advantages of coaxial cable are as follows: low cost, flexible design, easy maintenance, and high

compatibility. Its disadvantage is small coverage radius. The advantage of active distribution system is the

enlarged coverage area with the adaptation of trunk, and the disadvantage is extra interferences. Then the

system indexes are reduced and the maintenance difficulty is increased. The advantage of leaky cable is

evenly distributed signals, and its disadvantages are strict installation requirements and high cost.

Compared with traditional 2G indoor coverage, the UMTS network works at a high frequency band. Thus, the signal source is Compared with traditional 2G indoor coverage, the UMTS network works at a high frequency band. Thus, the signal source is

mainly provided by the remote RRU. In addition, the distribution systems are mainly passive systems owing to the self-interfering mainly provided by the remote RRU. In addition, the distribution systems are mainly passive systems owing to the self-interfering

feature of the UMTS. feature of the UMTS.

However, if the RRU is used as the signal source for large-scale buildings, then too many cells exist and would influence the However, if the RRU is used as the signal source for large-scale buildings, then too many cells exist and would influence the

large network. How to overcome this problem?large network. How to overcome this problem?

Solution: Multi-RRU Merge Technology (MRRU) at baseband unitSolution: Multi-RRU Merge Technology (MRRU) at baseband unit

13

Principles and Advantages of MRRU

Sm

all 2/3G

engineering construction w

orkload

Sm

all 2/3G

engineering construction w

orkload

Strong single cell

coverage capability

Strong single cell

coverage capability

Sim

plified design with

separated capacity and coverage

Sim

plified design with

separated capacity and coverage

Sm

ooth capacity expansion of the softw

are, and support 1-18 levels of capacity expansion

Sm

ooth capacity expansion of the softw

are, and support 1-18 levels of capacity expansion

ZTE MRRU technique is implemented in the baseband unit and will not raise the noise figure.ZTE MRRU technique is implemented in the baseband unit and will not raise the noise figure.

Downlinksignal

generation

Downlinksignalcopy

RRU

RRU

RRU

RAKEfinger

demodulation

Multi-path detection and assignation

MRC

Symbol rateprocess

andhigher layer

process

RNC

BBU

...

...

14

Advantages of MRRU in Indoor Coverage 1/2

Small engineering workload: The BBU and RRU are highly integrated, compact, and light. After the

optical fiber is used to replace the feeder, the cabling and engineering become easier, and the

workload is reduced.

Easy 2/3G indoor distribution system reconstruction: The BBUs can be installed integratedly, and

the RRU can be installed remotely. The optical fiber can be used as the transmission medium, which

efficiently reduces the feeder loss, and equivalently compensates the loss of 2GHZ high frequency

band. Then, the RRUs would have the same coverage capability as the signal source for 2G. The 2/3G

combining reconstruction becomes easier.

Good adaptability: The RRUs are independent from the active devices and can be installed in many

different scenarios. In actual network, few or no active devices are required, then the reduction of

network quality caused by too many active devices is avoided.

Separated coverage and capacity: Owing to the MRRU technique, one cell supports up to six RRUs,

then the coverage scope of one cell is greatly increased. In this way, the coverage and capacity can be

planned independently and the design of indoor distribution system is simplified.

15

Advantages of MRRU in Indoor Coverage 2/2

Good system performance: The performance of the main device is excellent, so the KPIs of the network

are guaranteed and the advantages of the diversified 3G services, especially the data services, are well

demonstrated.

Low O&M cost: The networking of BBU+RRU facilitates the centralized management and monitoring,

and provides low O&M cost. However, the active devices should be independently monitored, which

adds to the O&M difficulty of the network.

Smooth capacity upgrade: In the early stage, the cells can be flexibly divided based on the traffic

distribution conditions in the GSM network. The capacity expansion in the later stage can be performed

on the OMC, and no hardware modification is required.

Strong capacity expansion capability: Support 1-18 levels of capacity upgrade.

Comprehensive Scenario Solutions

Emergency CommunicationScenic Spots

Residential Building

Subway

Office Building/Hotel

Olympic Sports Center

Large Stadium

Scenario-Based Coverage Solution

Horizontal cell division

Vertical cell division

Block cell division

Coverage Solutions for Residential Areas

The attenuation of UMTS is large. Currently, the

frequency resources are limited, and it is hard to provide

coverage for high-level buildings in some scenarios.

Then, problems such as poor coverage, pilot pollution, or

no pilot would appear.

The distribution system with BBU+RRU and optical fiber

effectively helps to avoid ping-ping effect and coverage holes

for high-level buildings. In addition, it also solves the problem

of frequent handovers at high-level buildings, and reduces the

engineering difficulty.

Standard office buildings and high-level hotels

The indoor distribution system is used.

High-level residential buildings

The directional antennas facing upward are used at the lower

and middle levels, and the directional antennas facing

downward are used at rooftops to provide the coverage.

SolutionsSolutions

ProblemsProblems

Coverage Solution for Subway 1/2

How to deal with handover at high speed?

How to deal with the burse of traffic?

How to provide continuous coverage for platforms and tunnels?

Platform A

Ceiling antenna

Platform B

Ceiling antenna

Leaky cable

Leaky cable

Equipment room

Equipment room

Large coverage scope: Continuous coverage for platforms and tunnels is required.

The loss of the vehicle is huge and the high speed leads to the Doppler effect.

Multiple users would perform handovers simultaneously at high speed.

Then the handover success rate must be improved. The population density in the subway is high, and the capacity must be

designed based on the requirement at busy hours.

Multiple systems share the indoor system, and the equipment room resources are limited.

ScenarioScenario

http://zt.uutuu.com/zt/content/content_5843.htm

http://www.njbear.com/2/lib/200707/12/20070712253.htm

http://www.zhuoku.com/zhuomianbizhi/jingxuan-jingxuanyitu/20080404184803(3).htm

http://www.zhongyuan.net.cn/images/tjdtzjb/tjzjb_01.htm

Coverage Solution for Subway 2/2

In distribution systems with BBU+RRU and optical cable, the signal sources would access the PIO uniformly, thus the integrated coverage for subway platforms and tunnels are implemented.

POIPOI

The body loss and influences of Doppler effect are reduced.

Leakage cableLeakage cable

The compact BBU features large capacity, small volume and flexible installation. It can help to reduce the leasing cost of the equipment room.

Compact BBU with large capacity Compact BBU with large capacity

The high-power RRU can help to provide long coverage distance. In addition, the 3-carrier RRU is used to satisfy the capacity requirements.

High-power RRU with large capacityHigh-power RRU with large capacity

The traffic model for the subway would change with the time. At night, when the traffic is low, the intelligent power-saving technology is used to effectively reduce the power consumption of the equipment.

Intelligent nodesIntelligent nodes

Handover points can be flexibly set based on the engineering conditions, thus ensuring handover success rate.

Network planningNetwork planning

High-gain antenna at tunnel entrance

Coverage Solution for Tunnels

For tunnel coverage, the 6RRU mode can be used, which is:The RRU installed at the tunnel entrance will provide the coverage for the tunnel, and no handover would happen at the tunnel entrance.

The RRU installed inside the tunnel is connected with a power splitter. Then, leaky cables are connected to the power splitter to provide signals inside the tunnel.

RRU2 RRU3 RRU4

RRU1RRU6

RRU5

6RRU cell

In the tunnel, the leaky cable or directional antenna can be used to provide coverage in two directions. A single RRU can cover about 1km.

For tunnel groups, the MRRU technique can be used. Then multiple tunnels will be covered in the same cell, and no handover would happen.

MRRU can greatly expand the coverage capability of a single cell!MRRU can greatly expand the coverage capability of a single cell!

Coverage Solution for Large Stadium 1/3

Security requirements The BBUs are integratedly installed in the equipment room in the

functional zone or outside the Olympic Stadium. Then the O&M

personnel are at liberty to enter or depart.

The reliability of the RRU is high and can be flexibly installed within

the stadium.

Capacity requirements The scheduling scheme of the baseband capacity can be set based

on the traffic distribution and transfer of personnel.

The subscribers are concentrated and their amount is huge.

Quality requirements The coverage area is clear and open with no physical isolations. The

inter-subscriber interferences are huge.

ScenarioScenario


Weak electrical well

Stad

ium

RRU

BBUFlexible networking facilitates the speedy

construction of the stadium.The BBUs are integratedly installed, and the RRU are flexibly installed in the ceiling,

weak electrical well, electrical well, or equipment room.

Shared baseband helps to increase the resource

utilization rate. The baseband are integratedly installed, and the capacity is shared, then the

baseband resources can be adjusted based on the traffic changes. In such way, the

requirements of the ever-changing traffic are satisfied.

Separate planning of coverage and capacity facilitates

future capacity expansion. Coverage and capacity are independently planned. Then the UEs can access the

near indoor distribution system through the RRU. The capacity of the baseband

resources are integratedly expanded during the rush hour.

2/3G combining construction: Low cost and high

efficiencyThe 2G/3G network would share the distribution system, and this helps to

avoid the repeated construction. The RRUs are combined near the antenna,

then the feeder loss is reduced.

Auto recovery of the BBU: High reliability and

security The auto recovery of the baseband resources help to ensure available

resources for the system at any moment.

The auto power-off function of the boards can

help to reduce the power consumption. The auto power-off function helps to prolong the service life of the equipment

and reduces the power consumption of the base station.

The boards are powered off when the traffic volume reduces.

The boards are powered off when the traffic volume reduces.


Integrated coverage strategy, traffic migration, and

resource sharing Integrated coverage is realized for the stadium and functional zone. The

RRUs in these areas would share the baseband resources.

Interference suppression function helps to improve

the network performance and system capacity. Directional antennas are installed at the dome to cover the platform and

reduce the inter-cell interferences.

Reasonably planned cells help to maximize the

system capacity. The cells are reasonably planned after considering the interference and

capacity. In such way, the system capacity is maximized.

Separated coverage and capacity facilitates future

smooth capacity expansion. The BBU with large capacity is selected to satisfy the demand at rush hours.

The large-power RRU is also selected to compensate the feeder loss and

satisfy the coverage demand.

Integrated Coverage Solution for Cells

The co-channel networking is recommended.

The MRRU topology and cell divisions help to

reduce interferences.

Solution of indoor coverage + outdoor

distribution system is used to provide the

integrated coverage for cells.

Outdoor coverage is provided by “multiple

miniwatt antennas.” Some antennas are

installed at the rooftops to provide coverage

for the high levels, and some antennas are

installed on the ground to provide coverage

for lower levels.

It must be ensured that the UMTS outdoor

signals can be transmitted indoors by one-

time penetration. Then, antenna power is

reduced and the indoor coverage of

residential buildings is ensured.







Contents

2727

Coverage Solution for Grand Indoor Areas

This part takes Shenzhen Baoan Airport as an example. It occupies 11 sq.km of area, and the total area of terminal A and B are 146,000

m2. The passenger and cargo & mail throughput ranks the 4th place in China.

Signal propagation analysis: The area of the monolayer of Baoan Airport is huge, and the inner space is open and clear. In these areas,

the inter-cell signals must be well constrained, and the soft handover areas must be carefully planned to avoid pilot pollution.

Capacity analysis: The capacity requirement is huge, and the future capacity expansion is implemented by adding cells or carriers.

Cell planning requirements: The vertical cell division is used. Different cells cover different functional zones. The handover areas are set

in areas with low story height, such as the corridor. The cell number should also be controlled, so that there would not be too many cells on

the same floor. However, the planning difficulty is increased.

Coverage requirements for different RRUs in one cell: Each RRU would have its unique coverage area to avoid overlapping of signals

and this lays a solid foundation for future capacity expansion.

2828

Planning of Baoan Airport

Baoan Airport is divided into A, B, C, and D, four parts. The design involves three BBUs and 15 RRUs.

Since the cell number is well

constrained, the coverage of each

cell is clearly specified. The

BBU+RRU topology effectively

ensures the system performance.

The capacity expansion in the

later stage can be performed as

required. The cell expansion can

be performed by RRUs, and the

carrier expansion can be

performed by functional zones.

The capacity expansion can be

performed by the software at the

OMC, and no hardware

modification is required.

Inter-Frequency Networking for Lhotel Nina et Convention Center

Hotel overview: Located near the seashore in Hong

Kong Tsuen Wan District, it can provide you with an

complete view of Victoria Harbor, Tai Mo Shan, and

Rambler Channel. It is also equipped with the largest and

highest lobby in Hong Kong.

Networking: Located in the center of Hong Kong Tsuen

Wan District, this hotel is densely surrounded by base

stations. Therefore, the signal interference is severe, and

the outdoor signals cannot be controlled after they are

transmitted indoors. Under this condition, six RRUs are

integrated in one cell, and cell division can be performed

in the future along with the increasing of capacity.

Six RRUs are integrated in one cell, marked CELL1, and

its frequency differs from outdoors.

Then RRU1 in charge of 1F is resigned to a new cell,

CELL2, and its frequency is the same as outdoors. CELL2

works as a transitional cell.

Different signals exist at the entrance. Signals from

CELL3 are the strongest, 10dB higher than other cells.

In the lobby at the 1st floor, the outdoor signals are strong.

The pilot strength is around -70dBm to -80dBm under the

impact of outdoor signals.

If the simple inter-frequency networking solution is used,

then the hard handover failure rate at the elevator is high,

which is bad for outdoor to indoor handovers.

Transitional cells shall be introduced to solve the cell

handover problem.

Current distribution of signals

Transitional cell solution


CELL2 is the transitional cell.

Neighbor cell configuration in the lobby:

• CELL2 (F3) is configured as neighbor cell for CELL3 (F3).




31

The configuration of the outdoor cell (CELL3 ) remains the same.

Neighbor cell configuration: Uni-direaciton neighbor cell configured for transitional cells

The configuration of the outdoor cell (CELL3 ) remains the same.

Neighbor cell configuration: Uni-direaciton neighbor cell configured for transitional cells

Carrier Solution for Futian Shangri-La (Shenzhen)

32

The UMTS terminals meeting of China Unicom is held in Futian Shangri-La (Shenzhen).

Lots of 3G subscribers attend the meeting, and there are lots of 3G service exhibitions.

Therefore the requirement for network capacity is high and a four-carrier coverage

solution is recommended.

Carrier Solution for Futian Shangri-La (Shenzhen)

33

The planning is performed based on the multi-carrier bearing strategy and balanced coverage from

multiple bearers, and is as follows:

Planning UARFCN 10663 and 10638 to carry data services

Planning UARFCN 10713 and 10688 for CS services in priority

Stress Test

Carrier 10713 10688 10663 10638

Service priority CS (prioritized) Carrying HSPA

Services CS12.2k CS64k HSDPA HSUPA

Measured value

40 (Insufficient testing terminals)

24 9.3Mbps 3.7Mbps

The participants are very

interested in 3G services.

The OMC statistics shows that

the maximum number of

subscribers that are

simultaneously online reaches

58. The HSDPA flow rate

reaches 14.5M, and HSUPA

flow rate reaches 3.2M.

During the whole meeting, the QoS of the 3G services and the user perception are good. We have well satisfied the multiple services and large capacity requirements, and won the approval from Shenzhen branch of China Unicom.

Field demonstration

34

Application of MRRU Indoor Coverage Solution in China Unicom Projects

In actual planning, each RRU would be designed to cover 15,000m2 to 20,000m2 of area. In the

first phase of China Unicom project, about three RRUs would be used in each indoor coverage

spots and more than 90% of the indoor sites have only one cell.

Easy capacity expansion: When the capacity requirement increases, one RRU can be split into

multiple RRUs. When the physical topology is fixed, different cells can be distinguished based

on the ARFCNs. Then, the flexible indoor and outdoor inter-frequency networking is realized.

Speedy construction

of Indoor coverage

35

Conclusion

Indoor areas are the major places for subscribers to experience 3G services.

Thus, the proportion of 3G sites for indoor coverage is huge, and these sites

have carried a great amount of traffic volumes. Then, the coordinated

planning of indoor and outdoor coverage is essential for 3G network

optimization.

The network optimization penetrates the whole network construction process.

We can speedily enhance the network QoS by fully utilizing the functions of

different tools. Only in this way, can the sustained optimization be possible. MRRU is a highly efficient tool and is the product of rich indoor and outdoor

coordinated coverage experiences. Equipped with this tool, ZTE surely can

cooperate with China Unicom to build an excellent UMTS network!

ZTE UMTS Indoor Coverage Solution 201001V1.0

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