me slot domain for slot number 7. Timing advance can increase the transmission by as much as 63 bit times (63 x 3.69 microseconds). In GPRS Phase I, only the PTCHs will be used. The CCCHs of GSM will be used instead of the PCCCHs and the BCCH of the GSM will be used instead of the PBCC. All the necessary parameters for GPRS access will be broadcast on the BCCH using a System Information type 13 (SI 13) message. 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. Radio and MS-PCUSN Interfaces Radio and MS-PCUSN Interfaces Packet Logical Channels- PDCH Allocation The time slot configuration is declared for each time slot at the operations maintenance center for radio (OMC-R), initially found in GPRS Phase I. As shown in Figure 6-5, some time slots are reserved for the GSM system only (circuit-switched time slot); others are reserved for the GPRS system only (packet-switched time slot: PDCH); and some are used for a mix of each (first come first served). Future GPRS phases will likely have a dynamic time slot configuration, SO that all the channels may be allocated either for a circuit-switched logical channel or for a packet-switched logical channel, based on the capacity-on-demand principle (TCH/PDTCH configuration of the time slot at the OMC). The PDCH may be temporarily allocated (they share the same physical resource as circuit-switched services) due to their fast release. A cell supporting GPRS may allocate resources on one or several physi- cal channels in order to support the GPRS traffic. The physical channels shared by GPRS mobile stations are taken from a common pool of physical channels available within the cell. This allocation of physical channels to switched services and GPRS is carried out somewhat dynamically accord- ing to the capacity-on-demand principle. PDCH Allocation Figure 6-5 The sharing of time GSM TS (circuit switched) sl