A CDMA Mobile IP Packet Data Architecture

lular radio networks is expected to become a critical part of future wireless operators’ service offerings [1]. However, because mobility is an essential characteristic of cellular networks, operators are faced with a confusing array of choices for how to architect such a network. The Internet Engineering Task Force’s (IETF’s) Mobile IP protocol [2] provides a standard solution for wide-area mobility at the IP layer. However, Mobile IP by itself does not solve all problems involved in providing mobile Internet access to cellular users. A wide range of standards organizations are working on different approaches to the various issues, with the eventual goal of bringing these approaches into alignment as part of the International Mobile Telephony (IMT)-2000 effort for global standardization. The 3rd Generation Partnership Project 2 (3GPP2) is a consortium of national standards bodies tasked with developing architectures and standards for third-generation cellular networks. These standards will apply to networks that make use of the cdma2000 air interface, the high-speed code-division multiple access (CDMA) standard that is an evolution of IS-95 [3], and that have traditionally used American National Standards Institute (ANSI)-41 [4] for intersystem signaling. The cdma2000 standard supports higher speeds and a packet data mode that does not require a continuous circuit-like reservation of radio resources. The packet data network portion of this architecture will make use of the IETF’s Mobile IP protocol for network-layer mobility. Participants of 3GPP2 include the Telecommunications Industry Association (TIA) of North America, which prior to the formation of 3GPP2 was working on similar issues in its TR45.6 study group and elsewhere; the Telecommunications Technology Association (TTA) of Korea; the China Wireless Telecommunication Standard (CWTS) of China; and the Association of Radio Industries and Businesses (ARIB)/TTC groups of Japan. Once technical specifications are completed in 3GPP2, they will be standardized by the participating standards organizations. Another effort, known as 3GPP, is currently underway to standardize a network architecture known as the Universal Mobile Telecommunications System (UMTS) for Global System for Mobile Communications (GSM) and wideband CDMA (W-CDMA), a CDMA standard developed for Europe. Here the core network will be based on the General Packet Radio Service (GPRS) specification developed over the past few years by the European Telecommunications Standards Institute (ETSI) rather than on Mobile IP. Lastly, recent agreements between carriers have prompted an effort to create a global third-generation (G3G) CDMA wireless standard. This standard will encompass multiple modes of operation: a direct-spread mode, which is based on the W-CDMA of UMTS, and a multicarrier mode based on cdma2000. It is not yet apparent whether the network-layer mobility aspects of this architecture will be harmonized.