ghts reserved. Any use is subject to the Terms of Use as given at the website. Main GPRS Procedures Chapter 5 Figure 5-19 Server Web access on GPRS. PCUSN Attachment Ready PDP Context Activation Home Page Request Authenticated Subscriber such as the authentication and ciphering functions support these proce- dures. Moreover, DNS and DHCP services are provided on an as-needed basis. From this point, the next step is to allocate the radio resources and establish a data flow. Chapter 6, "Radio and MS-PCUSN Interfaces," delin- eates these resource assignments and the process of preparing to send and receive the data. 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. CHAPTER Radio and MS-PCUSN Interfaces Radio and MS-PCUSN Interfaces Chapter 6 Objectives Upon completion of this chapter, you should be able to State the different air interface requirements used. Understand the resource allocation methods. Describe how the timing advance is used in GPRS. Explain the coding schemes used in GPRS. Describe the function and role of the PCUSNs. Radio Link Control/Medium Access Control and Radio Frequency Layers This chapter focuses on the radio interface (the interface between the mobile station (MS) and the Base Transceiver System (BTS), which is func- tionally the Global System for Mobile Radio Frequency [GSM RF] layer) and on the mobile station to the packet control unit (PCU) interface, which is the Radio Link Control /Medium Access Control layers (RLC/MAC layer). To start the whole process off, the radio interface corresponds to the soft- ware in Layer 1 (GSM RF layer) between the mobile station and the BTS using the OSI model as the base reference, which is shown in Figure 6-1. The GSM RF layer manages the physical link between the mobile station and the Base Station Subsystem (BSS) (the combined BTS and BSC). This layer corresponds physically to the