【资料名称】：mss单元介绍

【资料作者】：FL

【资料日期】：2011-11-1

【资料语言】：中文

【资料格式】：DOC

【资料目录和简介】：

Base Station Signalling Unit (BSU)The BSU handles CCS7 signalling between the MSC and the Base Station Controllers (BSC). It also controls the PCMs running to the Base Station Subsystem (BSS). The basic configuration of the BSU can handle up to 16 signalling links and control up to 64 (ETSI)/84 (ANSI) external PCM lines.
Basic Data Communication Unit (BDCU)The BDCU contains communication links to the operation and maintenance network (analog/digital X.25; LAN/Ethernet), to the Short Message Center and to the Billing Center.
Cellular Management Unit (CMU)The CMU controls the cellular radio network and the Compact Data Service Units (CDSU) of the exchange. It also provides system support functions, such as Private Numbering Plan (PNP) translations.
Central Memory and Marker (CMM)The central memory handles the routing functions. The Marker controls and supervises the GSW, hunts for free circuits and is responsible for establishing and releasing all connections.
Verbal Announcement Generator (VANG)The VANG is a plug-in unit designed to meet the high announcement capacity requirements of mobile operators, particularly when offering IN services. The VANG uses recorded announcements stored in the files as PCM-coded data.
Clock System Unit (CLSU)The CLSUs generate the clock signals necessary for synchronising the functions of the Compact DX MSC and transmits them further to the CLBU units in the MMBC cabinet.
Clock and Alarm Buffer Unit (CLBU)The duplicated CLBUs distribute the clock signals (generated by the CLSUs) to the units in the same cabinet. The CLBU also collects the wired alarms from the units whose timing it handles and transfers them further to the OMU.
Synchronisation Signal Interface (SSIF-S)The optional SSIF-S units are used for generating additional synchronisation signals to be fed from the exchange to partner equipment. The SSIF-S receives an input signal from the CLBUs in the same cabinet and sends further four 2.048 MHz output signals from its four (two balanced plus two unbalanced) interfaces, all of which can be used simultaneously.
Compact Data Service Unit (CDSU)The CDSU offers standard GSM data services, which include modem-based digital connections towards the PSTN and digital connections towards the ISDN.
Echo Cancelling and Terminal (ECET)The ECETs perform the electrical synchronisation and adaptation of external PCM lines. Depending on the unit type used, they are able to do the HDB3 or AMI and B8ZS coding and decoding, insert the alarm bits in the outgoing direction and produce the PCM frame structure. The ECETs are also provided with an onboard echo canceller.
Exchange Terminal (ET)The ETs perform the electrical synchronisation and adaptation of external PCM lines. Depending on the unit type used, they are able to do the HDB3 or AMI and B8ZS coding and decoding, insert the alarm bits in the outgoing direction and produce the PCM frame structure.