JOURNAL OF TELECOMMUNICATIONS, VOLUME 5, ISSUE 2, NOVEMBER 2010 11 © 2010 JOT http://sites.google.com/site/journaloftelecommunications/ Analyze the Performance of Cellular IP Networks Mohammad Shahidul Islam Abstract— Mobile networks and the Internet are converging. This convergence challenges the QoS provisioning in such mobile IP networks. The future mobile Internet will include many portable devices connected to the global network. In order to achieve higher bandwidth for the users, the cell size will have to be limited. That leads to the creation of microcellular, or even picocellular environments, where the users move frequently among cells. This paper addresses problems that arise from the integration of mobile networks and the Internet, which are mainly due to user mobility. Also analyze the impact of handovers on different traffic types, such as CBR, VBR, as well as best-effort traffic. Index Terms—mobile network, IP network, network performances, network services, network QoS, cellular network, ——————————  —————————— 1 INTRODUCTION uture mobile networks should incorporate different traffic types, such as CBR, VBR, and best effort. Con- stant bit rate traffic is defined by its peak rate (which is also the mean rate) and it requires a constant data rate during the entire con- nection. However, even CBR traffic experiences jitter (packet delay variance) due to statistical multiplexing of flows at the network nodes. The descrip- tion of the variable rate traffic is more complex. A VBR flow experiences rate variations during the communica- tion. Best-effort flows utilize the bandwidth that is left after servicing the traffic with QoS guarantees. It is as- sumed that all calls have passed the admission control. 2 WHY IP NETWORKS? A telecommunications system has two main parts: switching part and transmission part. Switching systems may be exchanges in circuit switched telecommunications or routers in packet-based networks such as the Internet. Transmission systems has both wired or wireless links that interconnect the switching systems. Also, there are links that connect users, fixed and mobile, to the switch- ing systems, which forms the access network. For differ- ent media types and applications the 1. Equipment and installation costs; 2. Operation and maintenance costs. are lower when all content is carried over a single net- work than through different specialized networks be- cause of the statistical multiplexing that reduces trans- mission and switching costs. Accordingly, in the early 1990s European countries began to develop Asynchron- ous Transfer Mode (ATM) as a technology that would provide a single network for multiple traffic types. The idea was to take the concept of “a single socket in the wall” for telecommunication services, similar to an power distribution network where different appliances can be plug into the same socket. Although well-defined, ATM had high network costs and it lost the battle with a simp- ler and cheaper solution. That solution is the Internet Pro- tocol (IP), which is transparent to different multimedia types. Furthermore, IP provides simple interconnection and maintenance of IP networks (i.e., local area networks) as well as low-cost switching systems (i.e., IP routers). Also, together with its main overlaying protocols, TCP and User Datagram Protocol (UDP), it provides support for different traffic types. Gaining global popularity via the WWW and e-mail, IP emerged as the clear winner over its opponents such as the ATM concept [1]. 2 TRAFFIC ISSUES The Internet was created to be easy, simple and transpa- rent to different traffic types. But, considering the QoS, Internet basically supports only one traffic type for all, which is best-effort traffic. The creators of IP have left options for introducing multiple traffic classes via the Type of Service (ToS) field in IPv4 header format, and later on via the Differentiated Services (DS) field in IPv6 headers format. Integration of IP (i.e., Internet) and tele- communication networks for voice service highlights the QoS support in the Internet like never before. One traffic type for all does not well suit multiple applications. Also, some users may be willing to pay more for guaranteed QoS. The QoS support is especially important in mobile IP networks where resources are scarce and should not be wasted.[1] 3 SERVICE DIFFERENTIATION IN MOBILE PACKET NETWORKS Class differentiation in the wired Internet provides rela- ———————————————— • Mohammad Shahidul Islam Electronics and Telecommunication Department, Faculty of Science and Information Technology, Daffodil International University, Sukrabad, Dhaka-1207, Bangladesh F