Transcoding and rate adaptation Time and frequency synchronizing Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Introduction to GSM Chapter 1 Figure 1-12 The BTS. Voice through full- or half-rate services Decoding, decrypting, and equalizing received signals Random access detection Timing advances Uplink channel measurements The Base Station Controller (BSC) The Base Station Controller (BSC) manages the radio resources for one or more BTSs. It handles radio channel setup, frequency hopping, and han- dovers. The BSC is the connection between the mobile and the Mobile ser- vice Switching Center (MSC). The BSC also translates the 13-Kbps voice channel used over the radio link to the standard 64-Kbps channel used by the Public-Switched Telephone Network (PSDN) or ISDN. The BSC is between the BTS and the MSC, and provides radio resource management for the cells under its control. It assigns and releases frequencies and time slots for the MS. The BSC also handles intercell handover. It controls the power transmission of the BSS and MS in its area. The function of the BSC is to allocate the necessary time slots between the BTS and the MSC. It is a switching device that handles the radio resources. Additional functions include Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Introduction to GSM Introduction to GSM Control of frequency hopping Performing traffic concentration to reduce the number of lines from the Providing an interface to the Operations and Maintenance Center for the BSS Reallocation of frequencies among BTS Time and frequency synchronization Power management Time delay measurements of received signals from the mobile station Base Station Subsystem The Base Stat