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This paper introduces a mobility tracking mechanism that combines a movement-based location update policy with a selective paging scheme. Movement-based location update is selected for its simplicity. It does not require each mobile terminal to store information about the arrangement and the distance relationship of all cells. In fact, each mobile terminal(More)
—This paper proposes a new approach to simplify the two-dimensional random walk models capturing the movement of mobile users in Personal Communications Services (PCS) networks. Analytical models are proposed for the new random walks. For a PCS network with hexagonal configuration, our approach reduces the states of the two-dimensional random walk from (3 2(More)
In wireless data transmission, the capacity of wireless link is typically limited. Since many applications exhibit temporal locality for data access, the cache mechanism can be built in a wireless terminal to effectively reduce the data access time. This paper studies the cache performance of the wireless terminal by considering a business card application.(More)
Universal Mobile Telecommunications System (UMTS) supports IP multimedia services through IP Multimedia Core Network Subsystem (IMS). Since the IMS information is delivered through the General Packet Radio Service (GPRS) transport network, a UMTS Mobile Station (MS) must activate GPRS Packet Data Protocol (PDP) context before it can register to the IMS(More)
This paper describes mobility management for the third-generation mobile networks. We focus on the evolution from General Packet Radio Service (GPRS) to Universal Mobile Telecommunication System (UMTS). In this evolution, the radio access network UTRAN has been introduced, and radio-related management is moved from the core network to UTRAN. We elaborate on(More)
We propose an auxiliary strategy, called per-user forwarding, for locating users who move from place to place while using Personal Communications Services (PCS). The forwarding strategy augments the basic location strategy proposed in existing standards such as GSM and IS-41, with the objective of reducing network signalling and database loads in exchange(More)
— It is well known that, due to the mobility of a portable and limited channel availability, calls of portables may not be completed due to being blocked or terminated during the call initiation or the handover process. The characteristics of the call-completion and call-holding times for both a complete call and an incomplete call are of critical(More)
This paper describes the NCTUns simulation tool that facilitates the WiMAX studies of network behaviors and performance analysis. We compare NCTUns with ns-2, QualNet, and OPNET Modeler. The design paradigms of these tools are elaborated. Then we enumerate the WiMAX-related functions that can be simulated by these tools. The performance of NCTUns is studied(More)