GSM Timers Document - baixardoc

Mobilink Confidential Property

1

TIMERS

RF OPTIMIZATION ENGINEERING ACCESS NETWORK

PMCL [MOBILINK]


2

FOREWORD The document aims to describe various timers implemented in the GSM network. While reasonable efforts have been made to assure the accuracy of this document, PMCL assumes no liability resulting from any inaccuracies or omissions in this document, or from the use of the information obtained herein.

PMCL reserves the right to make changes from time to time in the content of this document and hereof with no obligation to notify any person of revisions or changes.


3

TABLE OF CONTENTS

1.0 Introduction 5 2.0 What does the manual cover? 5 3.0 Why the need to study timers? 5 4.0 Timer Categorization 6 4.1 Entity Based Categorization 6 4.2 Process Flow Based Categorization 6

5.0 Breakdown 7 6.0 GSM Timers 9 6.1 Call Setup 10 6.1.1 T3120 12 6.1.2 T3126 13 6.1.3 T3101 14 6.1.4 T3230 15 6.1.5 T303 16 6.1.6 T310 17 6.1.7 T11 18 6.1.8 T10 19 6.1.9 T313 20 6.1.10 T3107 21 6.1.11 T1 22 6.2 Call Clearing 23 6.2.1 T13 23 6.2.2 T3111 24 6.2.3 T3109 25 6.2.4 T3110 26 6.3 Handover 27 6.3.1 T3103 28 6.3.2 T8 29 6.3.3 T7 30 6.3.4 TQHO 31 6.3.5 T3121 32 6.4 GPRS 32 6.4.1 T3182 33 6.4.2 T3164 34 6.4.3 T3198 35 6.4.4 T3180 36 6.4.5 T3190 37 6.4.6 T3192 38 6.4.7 T3200 39


4

6.4.8 T3162 40 6.4.9 T3168 41 6.4.10 T3170 42 6.4.11 T3172 43 6.4.12 T3176 44 6.4.13 T3188 45 6.4.14 T3322 46 6.4.15 T3380 47 6.4.16 T3385 48 6.4.17 T3386 49 6.4.18 T3390 50 6.4.19 T3395 51 6.4.20 T3158 52 6.4.21 T3166 53 6.4.22 T3169 54 6.4.23 T3174 55 6.4.24 T3182 56 6.4.25 T3178 57 6.4.26 T3184 58 6.4.27 T3191 59 6.4.28 T3193 60 6.4.29 T3195 61 6.4.30 T3310 62 6.4.31 T3312 63 6.4.32 T3314 64 6.4.33 T3321 65 6.5 Miscellaneous 66 6.5.1 T3210 66 6.5.2 T3128 67 6.5.3 T3211 68 6.5.4 T3212 69 6.5.5 T3220 70

7.0 Compiled List 71 7.1 Motorola Timers List 71 7.2 Alcatel Timers List 73 7.3 Huawei Timers List 76


5

1.0 INTRODUCTION

Like any other wireless technology with a limited pool of resources, GSM resource allocation and termination depends primarily on timers. The functionality and protocols may vary, but the presence of timer based signaling and resource allocation is ubiquitous. Timer implementation is present in each domain of the GSM system from MS to NSS end.

2.0 WHAT DOES THIS MANUAL COVER?

This document aims to describe all the major BSS timers involved in the GSM architecture. The timers are categorized into different subgroups, depending upon their parent entity and the process flow they are involved in. The document proceeds further by giving a detailed explanation of each timer along with its implementation in the PMCL network.

3.0 WHY THE NEED TO STUDY TIMERS?

As already highlighted, timer implementation is present throughout the GSM architecture. Timers effect call setup procedures, handovers, call clearing, data usage (GPRS), VAS facilities; in short, everything that a customer might do to access and utilize the GSM network. Therefore, for a high quality network, it is imperative to have impeccable timing. Precise synchronization and timing improves call signal hand over performance between base stations; and, as an added benefit, reduces customer complaints. GSM networks are dependent on strict synchronization of the base stations to facilitate call handovers.

Furthermore, the reason for a deep understanding of timers is also

re‐enforced by the multi vendor implementation present at all levels of the network. Such a scenario demands all database discrepancies to be eliminated to ensure coherence and inter‐vendor compatibility.


6

4.0 TIMER CATEGORIZATION

4.1 ENTITY BASED CATEGORIZATION As highlighted earlier there are different ways of categorizing timers. One categorization can be done on the basis of entity which includes the following categories:

4.2 PROCESS FLOW BASED CATEGORIZATION A further classification of GSM timers can be done on the basis of

process flows involved in the system. These include the following basic categories:

• Call Processing Call Setup Call Release

• Handovers • GPRS • Miscellaneous


7

5.0 BREAKDOWN [PHASE 1]

The task of documenting the GSM timers is not an easy paced procedure. The project is divided into two phases. The first phase comprised of the research for all the timers involved from MS to BSS as per the international GSM standards. In the second phase, vendor implementations of these timers were taken into consideration. A complete overview of all the timers involved in Phase 1 is as under:

Timer Call Flow Vendor Timer's Name Category Default Value

Range

T3120 Call Setup

Motorola MS Timer MS Timer ‐ ‐Alcatel MS Timer MS Timer ‐ ‐

Huawei T3120 MS Timer Min is RACH T+2S; MAX 5

Min is RACH T+2S ;MAX 5

T3126 Call Setup

Motorola MS Timer MS Timer ‐ ‐Alcatel MS Timer MS Timer ‐ ‐

Huawei T3126 MS Timer Min is RACH T+2S MAX 5

Min is RACH T+2S MAX 5

T3122 Call Setup Motorola wait_indication_parameter BTS none 0 to 255 secAlcatel T3122 MS Timer ‐ 0 to 255 secHuawei T3122 Cell Timer 10 sec 0‐255 sec

T3101 Call Setup Motorola rr_t3101 BTS 5 sec 0 to 1000 secAlcatel T3101 BSC level 3 sec 0 to 25.5 secHuawei T3101 Cell Timer 3 sec 0.5 to 60 sec

T3230 Call Setup Motorola MS Timer MS Timer ‐ ‐Alcatel MS Timer MS Timer ‐ ‐Huawei T3230 MS Timer 15 sec 15 sec

T303 Call Setup Motorola MS Timer MS Timer ‐ ‐Alcatel MS Timer MS Timer ‐ ‐Huawei T303 MSC Timer 20 sec ‐

T310 Call Setup Motorola MS Timer MS Timer ‐ ‐Alcatel MS Timer MS Timer ‐ ‐Huawei T310 MSC Timer 20 sec ‐

T11 Call Setup Motorola bssmap_t11 BTS 28 sec 0 to 1000 secAlcatel T11 BSS 6 sec 0 to 19 secHuawei T11 BSC Timer 8 sec 1 to 30 sec

T10 Call Setup Motorola bssmap_t10 BTS 28 sec 0 to 1000 secAlcatel bssMapT10 BSS 14 sec ‐Huawei T10 BSC Timer 7 sec 1 to 20 sec

T313 Call Setup Motorola ‐ MSC timer ‐ ‐Alcatel T313 MS Timer ‐ ‐Huawei T313 MSC Timer 30 sec 30 sec

T8 Handover Motorola bssmap_t8 BTS 28 sec 0 to 1000 secAlcatel bssMapT8 BSS 14 sec 0 to 25.5 secHuawei T8 Cell Timer 10 sec 0.5 to 60 sec

T3103 Handover Motorola rr_t3103 BTS 30 sec 0 to 1000 sec


8

Alcatel T3103 BSS 16.5 sec 0 to 25.5 secHuawei T3103 Cell Timer 10 sec 0.5 to 60 sec

T1 GPRS Motorola bssmap_t1 BSC 30 sec

0 to 1000000 msec

Alcatel bssMapT1 BSS 16 sec 10 to 25.5 secHuawei T1 BSC Timer 30 sec 1 to 300 sec

T13 Call Clearing Motorola bssmap_t13 BSC 40 sec 0 to 1000 secAlcatel bssMapT13 BSS 15 sec 0 to 6553.5 secHuawei T13 BSC Timer 150 sec 1 to 300 sec

T7 Handover Motorola bssmap_t7 BSC 30 sec 0 to 1000 secAlcatel bssMapT7 BSS 5 sec 0 to 20 secHuawei T7 Cell Timer 10 sec 0.5 to 60 sec

TQHO Handover Motorola bssmap_tqho BSC 30 sec 0 to 1000 secAlcatel T_QHO BSS 3 sec 0 to 20 secHuawei TQHO BSC Timer 8 sec 1 to 30 sec

T3111 Call Clearing Motorola

rr_t3111_sd BTS 1.5 sec 0 to 1000 secrr_t3111_tch BTS 1.5 sec 0 to 1000 sec

Alcatel T3111 BSS 0.5 sec 0 to 2 secHuawei T3111 Cell Timer 1 sec 0.5 to 60 sec

T3109 Call Clearing Motorola rr_t3109 BTS 14.4 sec 0 to 1000 secAlcatel T3109 BSS 12 sec 0 to 35 secHuawei T3109 Cell Timer 27 sec 1‐35 sec

T3121 Handover Motorola ‐ MSC Timer ‐ ‐Alcatel T3121 BSS 14 sec 0 to 25.5 secHuawei T3121 Cell Timer 10 sec 0.5 to 60

T3107 Call Setup Motorola RRSM_T10 BTS 28 sec 0 to 1000 secAlcatel T3107 BSS 14 sec 0 to 25.5 secHuawei T3107 Cell Timer 10 sec 0.5 to 60 sec

T200 Configurational Motorola lapd_t200_timer BTS 2.5 sec 1.4 to 5 secAlcatel T200 BSS 0.3 sec 0.3 to 1 secHuawei T200 (FACCH/F/H) Cell Timer 0.05 sec 1 to 0.255 sec

T9101 Call Clearing Motorola ‐ ‐ ‐ ‐Alcatel T9101 Network 10 sec 0 to 6553.5 secHuawei SCCP_TREL(s) BSC Timer 15 sec 10 to 20 sec

T9104 Call Clearing

Motorola ‐ ‐ ‐ ‐Alcatel T9104 BSS 2 sec 0 to 25.5 sec

Huawei TCLEARREQ(BSC) BSC Timer 5 sec 1 to 150 sec

TNT3(MSC) MSC Timer 6 sec 1 to 120 sec

T9108 Call Clearing Motorola ‐ ‐ ‐ ‐Alcatel T9108 Network 3 sec 0 to 6553.5 secHuawei ‐ ‐ ‐ ‐

T3110 Call Clearing Motorola MS Timer MS Timer ‐ ‐Alcatel MS Timer MS Timer ‐ ‐Huawei T3110 MS Timer 10 sec 0.5 to 60 sec


9

6.0 GSM TIMERS

The description of GSM Timers in isolation can often lead to confusion for the engineer. To ensure uniformity and ease of understanding, a format has been used to describe in detail each timer. The format is as given below.

Timer Name

This field will include the name of the Timer, as used in the international GSM standards.

Category

This field will indicate the placement of the timers in the GSM network. For Example either a timer is used in Call Setup procedures or it is used to administer a Handover.

Start Event

This field will include the event which triggers the timer.

Stop Event

This field will include the event upon which, the timer stops.

Expiry Event

This is the event which takes place, once the timer has expired.

Optional field include the values used by the vendors, ranges and default values.


10

6.1 CALL PROCESSING

This section deals with timers that essentially make up the call request and call setup procedure. A skim through the call flow shown below will help give the reader an idea of the positioning of the timers and their importance.

Details for each of the mentioned timers will follow along with

suitable information on them.

GSM Timers Document - baixardoc

Documents

Transcript of GSM Timers Document - baixardoc