A mathematical formulation is developed for systematic tracking of the random movement of a mobile station in a cellular environment. It incorporates mobility parameters under the most generalized conditions, so that the model can be tailored to be applicable in most cellular environments. This mobility model is used to characterize different mobility-related traffic parameters in cellular systems. These include the distribution of the cell residence time of both new and handover calls, channel holding time, and the average number of handovers. It is shown that the cell residence time can be described by the generalized gamma distribution. It is also shown that the negative exponential distribution is a good approximation for describing the channel holding time.

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User mobility modeling and characterization of mobility patterns

Mobile wireless computing: challenges in data management

A communication system providing telephony communication across combined circuit switched and packet switched networks, such as a telephone network and the Internet, which are connectable to terminals, such as telephones and computers, for selective communication therebetween. The communication system includes an authorization and account control object in the packet switched network, multiple gateways between the circuit switched and packet switched networks providing controlled connectivity between those networks, and an information retrieval object in the packet switched network, wherein the authorization and account control object maintains a substantially real time record of user accounts and usage, and the information and retrieval object provides substantially real time retrieval of selected information from the authorization and account control object. The retrieval object provides on demand to terminals which provide authentication for access to an identified account information regarding that account. The information regarding the account is substantially real time information including information with respect to communications in progress, which are chargeable to the account which has been authenticated. The authorization and account control object is preferably a unitary logical object having distributed instances thereof handling multitudinous accounts of widely separated terminals. The retrieval object provides isolation of the authorization and account control object permitting simultaneous multitasking by the authorization and account control object and the retrieval object respectively.

Network session management

In future personal communications networks (PCNs) supporting network-wide handoffs, new and handoff requests will compete for connection resources in both the mobile and backbone networks. Forced call terminations due to handoff call blocking are generally more objectionable than new call blocking. The previously proposed guard channel scheme for radio channel allocation in cellular networks reduces handoff call blocking probability substantially at the expense of slight increases in new call blocking probability by giving resource access priority to handoff calls over new calls in call admission control. While the effectiveness of a fixed number of guard channels has been demonstrated under stationary traffic conditions, with nonstationary call arrival rates in a practical system, the achieved handoff call blocking probability may deviate significantly from the desired objective. We propose a novel dynamic guard channel scheme which adapts the number of guard channels in each cell according to the current estimate of the handoff call arrival rate derived from the current number of ongoing calls in neighboring cells and the mobility pattern, so as to keep the handoff call blocking probability close to the targeted objective while constraining the new call blocking probability to be below a given level. The proposed scheme is applicable to channel allocation over cellular mobile networks, and is extended to bandwidth allocation over the backbone network to enable a unified approach to prioritized call admission control over the ATM-based PCN.

Adaptive resource allocation for prioritized call admission over an ATM-based wireless PCN

Mobile Computing is a new emerging computing paradigm of the future. Data Management in this paradigm poses many challenging problems to the database community. In this paper we identify these new challenges and plan to investigate their technical significance. New research problems include management of location dependent data, wireless data broadcasting, disconnection management and energy efficient data access.

https://dl.acm.org/doi/pdf/10.1145/156883.156888

Data management for mobile computing

A distributed microcellular architecture based on the IEEE 802.6 Metropolitan Area Network (MAN) is proposed, and is shown to meet anticipated personal communications service (PCS) needs. A method is presented to calculate MAN coverage in urban areas, and is used to demonstrate coverage of approximately 50 city blocks per MAN. A distributed subscriber database architecture is proposed to facilitate call setup, tracking of roamers and handoffs. To fully utilize MAN bandwidth, a quick method for the heat stations to switch on/off isochronous slots is proposed to facilitate adaptation to PCS traffic level variations. Call setup and handoff procedures are detailed. The PCS signaling overhead is calculated to be 15% of the capacity required to carry voice traffic. >

Network architecture and signaling for wireless personal communications

The provision of advanced network services for personal communications is dependent upon the intelligent network (IN) The physical location of IN service control logic and databases in the personal communication network (PCN) substantially affects the signalling and processing delay and is considered critical given the anticipated demand for PCS The authors propose a MAN hierarchical design for network intelligence which avoids the traffic congestion associated with subscriber registration and call setup inherent in a centralized approach >

Distributed architectures and databases for intelligent personal communication networks

The current centralized wireless communication architectures are considered inappropriate to cope with the anticipated demand for personal communications. A distributed microcellular architecture is proposed, based on the IEEE 802.6 MAN. Initial traffic estimates indicate that the MAN would provide coverage for an urban area of 8*8 city blocks. It is shown that call control and management functions are dependent upon database distribution and class of handoff. >

L.J. Ng

Papers

Network architecture and signaling for wireless personal communications

Distributed architectures and databases for intelligent personal communication networks

A microcellular interconnection architecture for personal communications networks