钱用英语怎么说-nbna
1.
概述
作为一名网优工程师
,
需要牢牢掌握一个完整呼叫的信令流程
.
我们做
GSM
优
化
,
主要是对
Um
口要把握的
更深些
.
尤其是
Layer3
信令-也就是我们平常做路
测的工程师说的层
3
信令。关于层
3
信令,可以参考
p>
GSM
规范
04.08.
对层
3
信
令的准确理解
,
可以帮助我们快速分析和定位网络问题
.
2.
理论部分
2.1
一次完整的主叫流程(含切换)
IDLE
:
DL: SYSTEM INFORMATION TYPE 1
:包括小区信道描述和
RACH
控制参数
DL: SYSTEM INFORMATION TYPE 2
(
2bis
,
2ter
)
:邻小区
BCCH
频点描述,
RACH
控制信道,允许的
PLMN
(扩展邻小区
BCCH
频点描
述
+RACH
控制信道;扩展邻小
区<
/p>
BCCH
频点描述
2
)
DL:
SYSTEM
INFORMATION
TYPE
3
:
CI
,
L
AI
,控制信道描述,小区选择,小区选
择参数,
RACH
控制参数
DL:
SYSTEM INFORMATION TYPE 4
:
LA
I
,小区选择参数,
RACH
控制参数
,
CBCH
信道描述,
CBCH
移动配置
DL: SYSTEM
INFORMATION TYPE 7
:小区重选参数
DL: SYSTEM INFORMATION TYPE
8
:小区重选参数
UL:
Channel request
DL: Immediate assignmen
t
(
SDCCH
)
试呼:
UL:CM
service
request
(如果后面直接收到
System
Information
Type1
,则视
为起呼失败)
DL: CM service Request
DL:
CM service accept
DL: AUTHENTICATION
REQUEST
UL: AUTHENTICATION RESPONSE
DL: CIPHER MODE COMMAND
UL:
CIPHER MODE COMPLETE
DL: TMSI
REALLOCATION COMMAND
UL: TMSI
REALLOCATION COMPLETE
UL: SETUP
DL: CALL PROCEEDING
DL: ASSIGNMENT COMMAND
UL:
ASSIGNMENT COMPLETE
(
TCH
)
DL: ALERTING
成功起呼:
DL: CONNECT
(呼叫成功的标志
,
)
UL: CONNECT ACKNOWLEDGE
DL: SYSTEM INFORMATION TYPE 5
(
5bis
,
5ter
)
:邻近小区
BCCH
频点
描述(扩
展邻近小区
BCCH
频点描述
)
DL: SYSTEM INFORMATION
TYPE 6
:
CI
,
LAI
,小区参数设置
UL: MEASUREMENT REPORT
DL:Handover Command
DL:Physical Information
UL:Handover
Complete(
切换成功的标志
)
DL:Physical Information
DL:
SYSTEM INFORMATION TYPE 6
UL:
MEASUREMENT REPORT
DL:Disconnect
(收到该条消息或
Release
中的任何一条,则视
为正常释放,如
果两条消息均未收到,而是直接收到
Syste
m Information
Type1
,则视为一次
掉话)
UL:Release
DL:Release
Complete
DL:Channel Release
UL:Release Complete
2.2
一次正常的
LAR&RAU
信令流程:
Direction
Type
Layer 3 Message
UL
RR
Channel Request
DL
RR
Immediate
Assignment
UL
MM
Location Updating Request
UL
RR
Classmark Change
UL
RR
GPRS
Suspension Request
DL
MM
Authentication Request
UL
MM
Authentication Response
DL
MM
Identity
Request
UL
MM
Identity Respone
DL
MM
Location Updating accept
UL
MM
TMSI
Realocation Complete
DL
RR
Channel Release
UL
GPRS MM
Routing Area Update
Request
UL
RR
Channel Request
DL
RR
Immediate Assignment
DL
GPRS MM
Routing Area Update Accept
UL
GPRS MM
Routing Area Update Complete
2.3
各种情况对应的信令
?
掉话(既没有
Disconnect
,也没有
Release
,则视为掉话)
:
Paging
Request
→
Channel
Request
→
Immediate
Assignment
→
CM
Service
Request
→
CM
Service
Accept
→
p>
Setup
→
Assignment
p>
Command
→
Assignment
Complete
→
Connect/
Alerting
→
System Information
Type1
?
通话正常结束
(Disconnect
和
Release<
/p>
都有或只有其中一个都视为通话正常结
束
)
:
Paging
Request
→
Channel
Request
→
Immediate
Assignment
→
CM
Service
Request
→
CM
Service
Accept
→
p>
Setup
→
Assignment
p>
Command
→
Assignment
Complete
→
Alerting
→
Disconnect
→
Release
→
Release
Complete
→
Channel
Release
?
呼叫失败:
Paging
Request
→
Channel
Request
→
Immediate
Assignment
→
CM
Service
Request
→
System Information T
ype1
(在一次呼叫过程中,若连续出
现多个
CM Service
Request
,则视为一次呼叫失败)
?
呼叫成功:
Paging
Request
→
Channel
Request
→
Immediate
Assignment
→
CM
Service
Request
→
CM
Service
Accept
→
p>
Setup
→
Assignment
p>
Command
→
Assignment
Complete
→
Connect/Alerting
?
切换成功:
Handover
Command
→
Handover Complete
?
切换失败:
Handover
Command
→
Handover Failure