Kpi for Evdo

Key Performance Indicators for EVDO

© 2006, ZTE Corporation. All rights reserved.

Contents

Various Performance Area

Types of KPI

1. Call Processing based

2. Ran Performance based

3. Coverage based



1. Session:

1xEV-DO Session Setup

An AT must establish a 1xEV-DO session with a DO-RNC before the AT is

allowed to access the 1xEV-DO network. During the 1xEV-DO session

setup process, an UATI is assigned. Configuration is negotiated.

A PPP session setup will also be attempted. The PPP session setup may

or may not succeed, but it will not affect the1xEV-DO session setup.

1xEV-DO Session Close

The 1xEV-DO session can be closed normally by either the AT or AN. The

1xEV-DO session will also be closed under error condition.


Various Performance Area2. Connection:

1xEV-DO Connection Setup

The AT originates a connection setup by sending a ConnectionRequest

message to the AN. For AT terminated connection setup, either a normal

setup or a Fast Connect can be performed. In a normal setup, the AN

pages the AT. The AT then responses with a ConnectionRequest

message. In a Fast Connect, no Page message nor ConnectionRequest

message is involved. The AN sends a TrafficChannelAssignment message

directly.

Because in a normal setup, the ConnectionRequest message is involved

in both the AT originated or AT terminated connection setup, the following

performance metrics will not distinguish between an AT origination or an

AT termination. A Fast Connect is always associated with AT terminated

connection setup.


1xEV-DO Connection Close

A 1xEV-DO connection can be closed by either the AT or AN. The

connection close

can be a normal close initiated by the user or as a result of inactivity. The

connection

will also be terminated when an error condition occurs.

1xEV-DO Connection Setup Performance

Connection Setup Success Rate

Defines the success rate that the 1xEV-DO connections are opened.

The Access Failure Rate

measures the RF related failure rate excluding the resource blocks and

other non-RF related failures.



Handoff:

Serving Sector Switching and Softer/Soft Handoff Performance

Forward Link Handoff – Virtual Handoff (Sector Switching)

In 1xEV-DO, there is no soft handoff on the forward link. The AT indicates

to the AN the sector that it has selected, and the AN does the sector

switching. On the reverse direction, there are similar softer and soft

handoffs as in 1xRTT/IS-95.

Reverse Link Soft Handoff Performance

In 1xEV-DO, reverse link soft/softer handoff is initiated by AT sending a

RouteUpdate message to request the addition or removal of pilots to its

active set. Each RouteUpdate message is counted as a handoff attempt

regardless of the number of pilots in the message. A handoff is

considered to be successful if ALL the requested pilots are added (or

removed). The handoff is considered to be failed even if only one of the

pilots is not successfully added (or removed) for any reason. The

connection will be closed when the handoff fails.



Paging:

Paging Performance does not measure the DO-RNC initiated dormant to

active transition performance. In Release 2.0, page retry is not

supported. When an AT fails to respond to a page, the buffered packets

will be flushed. No page retry will be attempted. If there is no more data

packet coming in, then no addition action will be taken. If the packets

keep on coming in from the A10 connection, a new page attempt will be

initiated. However this attempt is considered as a new page rather than

the retry. When the DO-RNC attempts to set up a connection to an AT, it

can perform either a normal setup involving paging the AT, or a Fast

Connect without paging the AT.



Control Channel (CCH)Usage:

The Control Channel (CCH) in 1xEV-DO is similar to the Paging Channel

in 1xRTT. However, the CCH is time multiplexed with the Forward Traffic

Channel (FTC), and occupies variable portion of the forward link

bandwidth depending on the CCH traffic. The forward link bandwidth

used for CCH will not be available for the FTC. Therefore, the CCH

usage has a direct impact on the possible maximum FTC throughput.

Access Channel (ACH) Usage:

The 1xEV-DO Access Channel (ACH) is very similar to the Access

Channel in 1xRTT. However, the Access Channel probe size can be

variable in 1xEV-DO. The possible number of ACH probes that can be

sent (an indication of ACH capacity) in a certain period can be variable.

As a result, an ACH occupancy may not be defined. Only statistics on the

received probes are considered




PPP Link (Point to Point Link Protocol):

PPP comprises of three main protocols:

1. A protocol for encapsulating datagrams over serial links

2. A Link Control Protocol (LCP) for establishing, configuring, and

testing the data-link connection

3. A family of Network Control Protocols (NCPs) for establishing and

configuring different network-layer protocols.

IPCP (IP Control Protocol) is mainly used as NCP.



PPP Link Establishment Steps:

In order to establish communications over a point-to-point link, each end of the PPP link must first send LCP packets to configure and test the data link.

After the link has been established and optional facilities have been negotiated as needed by the LCP, PPP must send NCP packets to choose and configure one or more network-layer protocols.

Once each of the chosen network-layer protocols has been configured, datagrams from each network-layer protocol can be sent over the link.

The link will remain configured for communications until explicit LCP or NCP packets close the link down, or until some external event occurs (an inactivity timer expires or network administrator intervention).


IPCP: A PPP Network Control Protocol (NCP) for IP

The IP Control Protocol (IPCP) is responsible for configuring,

enabling, and disabling the IP protocol modules on both ends of

the point-to-point link.

IPCP uses the same packet exchange machanism as the Link

Control Protocol (LCP).

IPCP packets may not be exchanged until PPP has reached the

Network-Layer Protocol phase. IPCP packets received before this

phase is reached should be silently discarded.



1. Call Processing KPI

2. Ran Performance KPI

3. Coverage KPI

Call Processing KPI

• 1x EV-DO Session Setup Time

• AT Initiated Connection Setup Time

• AN Initiated Connection Setup Time

• PPP Session Setup Time

• PPP Setup Failure Rate

• Round Trip Time

Ran Performance KPI

• AT Initiated Connection Setup Success Rate

• AN Initiated Connection Setup Success Rate

• Connection Drop Rate

• Reverse Link Soft/Softer Handoff Success Rate

• DRC Re-pointing Success Rate(Virtual Soft and Softer)

Coverage KPI

• SINR Distribution

• Receive Power Distribution

• Transmit Power Distribution

• DRC Distribution

• Active Set Size Distribution

• PER Distribution

Types of KPI


CALL PROCESSING

BASED KPI


KPI 1. 1x EVDO Session Setup Time

Session Setup - Message Flow

1x EVDO

Session

Setup

Time < 6

sec for

90%

attempts


KPI 2. AT Initiated Connection Setup Time

AT

Initiated

Connecti

on Setup

Time <

1.5 sec

for 90%

attempts


KPI 3. AT Terminated Connection Setup Time

Page

AT

Terminate

d

Connectio

n Setup

Time < 5

sec for

90%

attempts


KPI 4. PPP Session Setup Time

PPP

Session

Setup time

< 3 sec for

90%

attempts


KPI 5. PPP Setup Failure Rate

KPI 6. Round Trip Time

Formula = No of Failed PPP Setup attempt/No of Total PPP Setup Attempts

ZTE System Threshold: <5%

It is the Latency time for ICMP (Internet Control Message Protocol) Payload of

various size (8 Bytes, 32 Bytes, 56 Bytes)

As per Qualcomm Standard,

For 08 Byte ICMP Payload, Average RTD = 70 – 130 msec



With ICMP Loss Rate <= 0.5%


COVERAGE

BASED KPI


RAN PERFORMANCE

BASED KPI


SR NO KPI FORMULA

QUALCOMM

or ZTE

THRESHOLD

1 AT Initiated

Connection Setup

Success Rate

num of successful connection setups / num of AT

initiated connection attempts

≥95%

2 AN Initiated

Connection Setup

Success Rate

num of successful connection setups / num of

total AN Pages

≥95%

3 Connection Drop

Rate

(num of successful connection setups - num of

normal connection close) / (num of successful

connection setups)

<5%

4 Reverse Link Soft

(or softer) Handoff

Success Rate

1 - (num of failed soft(or softer) handoffs/ total

num of handoffs)

>95%

5 DRC Re-pointing

Succes Rate(Virtual

Soft and Softer)

1- (Fwd sector switching failures / (fwd sector

switching failures + fwd sector switching

successes))

>99%


Other Important KPI:

Other Important KPIs needs to be monitored are as follows. Its descriptions is

given in inserted excel file:

1.Quick Connect Failure Rate [%]

2.Fast Connect Failure Rate [%]

3.Connection Block Rate [%]

4.Effective Page Success Rate [%]

5.UATI Assignment Failure Rate [%]

6.Session Configuration Failure Rate [%]

7.A13 Session Transfer Failure Rate [%]

8.FL Slot Utilization including any CC transmission Histogram [%]

9.FL & RL average Sector throughput at RLP [kbps]

10.FL & RL average Sector throughput at Physical Layer [kbps]

11.Soft & Softer Handoff Failures [%]

12.Backhaul unavailability Rate [%]

Kpi for Evdo

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