The TD-SCDMA radio access technology in the GSM network

摘要

Third Generation Partnership Projects, 3GPP and 3GPP2, were founded at the purpose to deliver a global 3G mobile radio standard, merging the work produced so far by the joining Organisational Partners (1). In the framework of this activity, 3GPP has delivered the UTRA standard (2) which includes: the Frequency Division Duplex mode (FDD), based on WCDMA (3), and the Time Division Duplex mode (TDD), based on TD-CDMA (4). The TDD mode comprises: the High Chip Rate (HCR) TDD and the Low Chip Rate (LCR) TDD, characterised by a different chip rate (respectively 3.84 and 1.28 Mchipls) and frame duration (respectively 10 and 5 ms). The LCR TDD, promoted by CWTS, is currently in Release 4 of the UTRA. In parallel to the 3GPP activity, CWTS is working at the definition of a regional standard, the TD-SCDMA System Mobile (TSM), which combines the LCR TDD Physical Layer with the GSM Higher Layers. This paper shows how a GSM network can support the TSM technology, describing the most significant differences of TSM, respect to the LCR TDD Physical Layer and GSM higher protocol layers.