Huawei 2G Parameters Introduction

(1)

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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

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CONTENT

System Information Parameters

Handover algorithm Parameters

Power Control algorithm Parameters

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RACH control parameters



RACH control parameters

include:

► Maximum re-transmitting times

(MAX retrans)



limit of times that MS is allowed to

send Channel Request in one

immediate assignment procedure

► Extended transmission

timeslots (Tx_interger)



calculate the number of timeslots in

the interval between multiple

S

Tx_Integer Not Combined CCH Combined CCH

3，8，14，50 55 41

4，9，16， 76 52

► 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

use early Class mark sending

► MBR



inform MS to report the information about

neighboring cells of multiband.

(6)

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

(7)

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

consideration.

► 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.

(8)

Cell select and reselect parameters



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

max{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

(9)

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)

(10)

CONTENT

System Information Parameters

Handover algorithm Parameters

Power Control algorithm Parameters

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General process of HO Algorithm

M.R.

preprocessing

Penalty

processing

Basic ranking

Secondary

ranking

TA emergency HO

BQ emergency HO

RSD emergency

HO

Interf. emergency HO

Edge HO

Layer HO

PBGT HO

OM forced HO

Directed retry

Overlaid/underlaid HO

Fast moving MS

HO

1

(12)

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

Cell Layer Priority

Co-BSC/MSC

Cell Type

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HW handover parameter

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CONTENT

System Information Parameters

Handover algorithm Parameters

Power Control algorithm Parameters

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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

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

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_Qul

↑

max(AdjStep_Lev,AdjStep_Qul)

↑AdjStep_Lev

No action

↑AdjStep_Lev

No action

↓ AdjStep_Qul

No action

↑ AdjStep_Qul

No action

(18)

HW II Power Control

Qual

Lev ↑ (1)

Max ↓ (2)

Lev ↓ (1)

Qual ↓ (3)

No Action

Qual ↑ (3)

Max ↑ (2)

0 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.

(19)

HW II Power Control



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

Qual

Lev ↑ (1)

Max ↓ (2)

Lev ↓ (1)

Qual ↓ (3)

No Action

0 Qual. upper Thrsh.

Qual. bad TrigThrsh

Qual. bad UpLEVDiff

Qual. lower

Thrsh.

(20)

CONTENT

System Information Parameters

Handover algorithm Parameters

Power Control algorithm Parameters

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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



BSC channel allocation algorithm selects the channel for allocation

by considering

(22)

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,

>TCHH,

TCHF<->SDCCH

(23)

Dynamic allocation of SDCCH



Approach

► If SDCCH allows dynamic

allocation and satisfy the

following conditions:



Number of SDCCH <=

idle SD

Thrsh



Number of existing SDCCH in

the cell <

Cell SD Maximum

;



Purpose

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

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

(24)

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

channel allocation

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

service quality better:

(25)

Dynamic convert between TCHF & TCHH



TCH Traffic Thrsh(%)

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

channel reaches or exceeds this threshold, the dual rate call is allocated with the

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



Enhanced Chan. Convert Enable

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

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