huawei 2g parameters introduction

HUAWEI TECHNOLOGIES CO., LTD.

Huawei GSM Parameters Introduction

All Rights Reserved © 2007, Huawei Technologies CO., LTD.

Overview

What is Parameter?

► The height, down tilt, longitude \ latitude… -> Engineer Parameter

► How to access to network, when to handover… -> Radio Parameter

► We use parameter to control, adjust and optimize the network.

Compared with other equipment vendor, how about Huawei

Parameter?

Compared with other equipment vendor, how about Huawei

Algorithm?


CONTENT

System Information Parameters

Handover algorithm Parameters

Power Control algorithm Parameters

Resource allocation algorithm Parameters


System Information Signal


RACH control parameters

RACH control parameters inclu

de:

► Maximum re-transmitting times

(MAX retrans) limit of times that MS is allowed to s

end Channel Request in one immed

iate assignment procedure

► Extended transmission timeslot

s (Tx_interger) calculate the number of timeslots in

the interval between multiple chann

el requests sent by MS

S

Tx_Integer Not Combined CCH Combined CCH

3 ， 8 ， 14 ， 50

55 41

4 ， 9 ， 16，

76 52

5 ， 10 ， 20，

109 58

6 ， 11 ， 25，

163 86

7 ， 12 ， 32，

217 115

► Common access control level (ACC) permit or forbid the network access of some

common level users

► ECSC indicates if an MS in the cell is allowed to us

e early Class mark sending

► MBR inform MS to report the information about n

eighboring cells of multiband.


Control channel description parameters

Common Control Channel

Configuration (CCCH_CONF)

► 0 Not-Combined -> 9 CCCH block

► 1 Combined -> 3 CCCH block

► CBCH combine with BCCH or

SDCCH?

Access Granted Blocks Reserved

(BS_AG_BLKS_RES)

► number of CCCH channel message

blocks that are reserved in one multi-

frame for access granted channels

Paging Channel Multi-frames

(BS_PA_MFRAMES)

► number of multi-frames used as a

cycle of paging sub-channels


Cell option parameters

Cell option contains the following parameters:

► Power control indication (PWRC) When it is set to “No”, it means the influence of receiving level on BCCH is not in consi

deration.

► Discontinuous transmission (DTX)

► NCC Permitted If a neighbor cell’s NCC is permitted, MS will report MRs of it to the network

► Radio link timeout It is a timer used to determine whether the downlink radio link connection fails.

SACCH Multi-Frames used to determine the uplink radio link connection fails.

When AMR, How to modify this parameter?


Cell select and reselect parameters

C1(n) = RxLev(n) – RxLev_Access_Min(n) –m

ax{0, MS_Txpwr_Max_CCH(n) – P}

C2 = C1 + CRO –TO *H (PT – T)

(PT < 620s)

► H(x) = 0: for the serving cell and if x <0

H(x) = 1: otherwise

C2 = C1 – CRO (PT=620s)

► Use Parameters which are broadcasted on the

BCCH if PI = 1, otherwise C2 = C1

Cell A

Cell B


Cell select and reselect parameters

Location update related parameters

► IMSI Attach-Detach Allowed (ATT) inform MS whether IMSI attach-detach is allowed in this cell

► Periodic Location Update Timer (T3212) Periodic Location Update Timer. It defines the interval of periodic location update.

The two parameters must be set to

the same value in one LAC!


CONTENT






General process of HO Algorithm

M.R.preprocessing

Penalty processing

Basic ranking

Secondary ranking

HO judgment

TA emergency HO

BQ emergency HO

RSD emergency HO

Interf. emergency HO

Load Sharing HO

Edge HO

Layer HO

PBGT HO

Processing program

OM forced HO

Directed retry

Overlaid/underlaid HO

Fast moving MS HO

1

1


Ranking of Candidate Cell

The candidate cell is ranked by the some rules. It is for both serving

cell and the neighbor cells.

The ranking processes include:

► M rule: RX_LEV (n) > MSRXMIN(n) + OFFSET

► K rule: Ranked in descending order according to the rx_lev only

► 16 bits ranking: The smaller the value is, the higher the priority

16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1

Rx Lev

HO hysteresis

Cell Layer Priority

Load

Co-BSC/MSCCell Type(Extension,Normal)

Layer HOReserve bit


HW handover parameter

Do the process in BTS side


HW handover parameter


CONTENT






Advantage of Huawei II power control algorithm

HW II power control has the following advantages:

► Measurement report compensation -- makes power control judgment

more precise

► Measurement report prediction --to avoid power control later than

needed, the delay is dangerous in case of poor level or bad quality

► Power control expected signal level and quality threshold falls within a

band, this avoids receiving signal level fluctuate up and down frequently


General power control judgment

Power control by receiving

level

Power control by receiving

quality

Power control by signal level

and quality

↓ AdjStep_Lev ↓ AdjStep_Qul ↓

max(AdjStep_Lev,AdjStep_Qul)

↓ AdjStep_Lev ↑ AdjStep_Qul No action

↓ AdjStep_Lev No action ↓ AdjStep_Lev

↑ AdjStep_Lev ↓ AdjStep_Qul ↑ AdjStep_Lev

↑ AdjStep_Lev ↑ AdjStep_Qul ↑

max(AdjStep_Lev,AdjStep_Qul)

↑ AdjStep_Lev No action ↑ AdjStep_Lev

No action ↓ AdjStep_Qul ↓ AdjStep_Qul

No action ↑ AdjStep_Qul ↑ AdjStep_Qul

No action No action No action

HW I I Power Control


HW II Power Control

Lev

Qual

Lev ↑ (1)

Max ↓ (2)

Lev ↓ (1)

Qual ↓ (3)

No Action

No ActionQual ↑ (3)Max ↑ (2)

0

7

0 63

Target level = (RX_LEV lower Thrsh. + RX_LEV upper Thrsh.)/2

This offset used to anti ping pong power control

Qual. upper Thrsh.

Qual. lower Thrsh.

RX_LEV lower Thrsh. RX_LEV upper Thrsh.


HW II Power Control

Qual. bad TrigThrsh makes PC process triggered earlier when the quality is bad.

Lev

Qual

Lev ↑ (1)

Max ↓ (2)

Lev ↓ (1)

Qual ↓ (3)

No Action

No ActionQual ↑ (3)Max ↑ (2)

0

7

0 63

Qual. upper Thrsh.

RX_LEV lower Thrsh. RX_LEV upper Thrsh.

Qual. bad TrigThrsh

Qual. bad UpLEVDiffQual. lower Thrsh.


CONTENT






HW II channel allocation algorithm

Channel interference (idle mode

measurement band1~5)

Configuration (BCCH TRX \

hopping sequence)

History record (allocate failure\

call drop)

Load distribution (as even as

possible)

MS transmitted power

Based on the specific call event

and environment. (Intra cell HO)

Etc.

BSC channel allocation algorithm selects the channel for allocation

by considering


Dynamic allocation of channel resource 　

PDCH

TCHF

TCHH

SDCCH

real line stand for real-time conversion broken line stand for not real-time conversion

Huawei has good mechanism to

dynamic allocate the channel

resource.

Support dynamic allocation

between PDCH<->TCHH\F,

TCHF<->TCHH, TCHF<-

>SDCCH

Make the channel usage more efficientMake the channel usage more efficient


Dynamic allocation of SDCCH

Approach

► If SDCCH allows dynamic allo

cation and satisfy the followin

g conditions: Number of SDCCH <= idle SD T

hrsh

Number of existing SDCCH in th

e cell < Cell SD Maximum;

Number of idle TCH is greater th

an 4 or greater than the number

of configuration carriers.

Purpose

► When the request of SDCCH in a cell suddenly increases, TCH can convert into SD

CCH so as to ensure that most of the users can access the network


Dynamic allocation between TCH & PDCH

Dynamic PDCH and PDTCH

► When dynamic PDCH is not used for packet service, it equal

to TCH.

Packet service priority (PCU parameter)

► This parameter determine the priority between PS and CS ch

annel allocation

► For vip cell, set PS priority higher than CS to make the GPRS

service quality better:

Command: pcu set priv <LCNo> 2 120 2000 2400


Dynamic convert between TCHF & TCHH

TCH Traffic Thrsh(%)

► During the allocation of the BSC channel, if the occupation rate of current channe

l reaches or exceeds this threshold, the dual rate call is allocated with the half rat

e channel preferentially. Otherwise, allocate full rate channel preferentially.

Enhanced Chan. Convert Enable

► This parameter determines whether to allow the intra-cell handover to combine th

e call on the two SINGLE timeslots into one Couple timeslot to covert the call into

TCHF when there is no idle TCHF for allocation.

Couple Channel

► when one timeslot is divided into two TCHHs and the two TCHHs are idle. The tw

o TCHH are called Couple.

Single Channel

► when one timeslot is divided into two TCHHs, and one TCHH is busy and the oth

er is idle. The idle one is called Single.


Dynamic allocation between TCHF & TCHH

Has idle FR channel

Channel request (FR only)

Allocate FR channel

Has couple channel

Convert couple channel to FR

channel and allocate it to the c

all request

HR channel number >

1

Refuse the

request

Yes

Yes

Yes

No

No

No

Trigger intra-cell HO, in order t

o make a couple channel and

convert it to FR. Allocate it to t

he call request



Has idle FR channel

Channel request (FR prefer)

Allocate FR channel

Has couple channel

Convert couple channel to FR cha

nnel and allocate it to the call req

uest

HR channel number > 1

Trigger intra-cell HO, in order to

make a couple channel and conv

ert it to FR. Allocate it to the call r

equest

Yes

Yes

No

No

No

Allocate HR channel

Yes



Has idle single

Channel request (HR

request)

Allocate HR channel

Has idle coupleAllocate half of couple channel

Has idle FR channel

Convert FR channel to couple

channel, and then allocate half

of couple channel

Channel allocation failure

Yes

Yes

Yes

No

No

No


Thank You

huawei 2g parameters introduction

Documents

action power

rxlev lower

idle fr channel

rxlev upper

action adjstepqul

allocate hr

hw handover

lower thrsh