Jyhi-Kong Wey

Clone terminator: an authentication service for advanced mobile phone system

In this paper we propose an innovative centralized, proof-by-knowledge authentication service by using IN to terminate the clone problem in AMPS. With our proposed service, the authentication information of mobile stations is transmitted on the control channels and voice channels separately and asynchronously. Since the number of voice channels is relatively larger than the number of control channels, the authentication information is hard to eavesdrop. In addition, the voice channels have the permutation property to protect from secure attack. Therefore, the mobile stations cannot be purposely duplicated by eavesdropping messages or copying the serial numbers and mobile identification numbers transmitted by the control channels on the air. Furthermore, the security of the proposed service is completed by the combination of mobile services and IN services.

Traffic impacts of international roaming on mobile and personal communications with distributed data management

In this paper, we propose four network interconnection scenarios and the related signaling aspects for the international roaming traffic in mobile and personal communications. With or without international gateway relay nodes summarized from the proposed scenarios, we also derive three international roaming network sets {IR1, IR2, IR3} for the observed signaling traffic model with two‐level databases. Based on the proposed performance metrics, analysis results show that under some reasonable assumptions the signaling traffic of international roaming is significantly impacted by the related gateway relay nodes and databases. In addition, the studied cache data management strategy at VLR can reduce the impacts of the signaling traffic of query operation, but the caching approach cannot improve the performance of update operation. Furthermore, the performance of proposed standalone STP scenario is better than that of integrated STP scenario for the international network connection.

Evolution of intelligent network deployment in Taiwan's mobile networks

IN services have been launched in the wired network for more than four years in Taiwan. The number of wired IN service subscribers grows slowly. However, the IN-based prepaid service for mobile subscribers has more than 1 million users in its first launch year. The rate of prepaid service subscribers to total mobile subscribers is greater than sixteen percent and grows predictably. In addition, many value-added services are introduced to differentiate mobile networks. These value-added services will be enhanced as the intelligence capability of IN can be improved. There is no doubt that services based on IN will be prosperous and welcomed as Internet fever warms up in the wired-wireless convergent network.

On the traffic estimation and engineering of GSM network

We propose a detailed analysis and estimation of SS7 signaling traffic performance on GSM databases in Taiwan. With the network engineering and configuration, a fluid flow mobility model is employed to investigate the performance of signaling traffic between databases such as home location registers (HLRs), visitor location registers (VLRs), and equipment identification register (EIR). We also propose the mobility-related signaling traffic on HLRs, VLRs, and EIR to calculate transaction message loads per second on these databases. In addition, the minimum numbers of signaling link required for each VLR, HLR and EIR are estimated with both low and high mobile speeds as well as various average call rates. Furthermore, the estimation and engineering of the processing time capacity of these databases are investigated under various average call rates. Finally, the results in our study are proved to efficiently support the engineered and implementation plan of the existing Taiwans GSM network.

Mobility traffic analysis for PACS using various subscriber profiles

The signaling traffic between access managers (AMs) and home location register (HLR) are SS7 signaling messages in the personal access communication system (PACS) system. These signaling messages are for the transportation of subscriber unit (SU) registration, call origination, and call delivery, and also for authentication in these procedures. The signaling traffic is referred to mobility management traffic. In addition, the performance of mobility management traffic plays an essential role in the performance of the whole PACS system network. In this paper, we propose an M/G/1 traffic analysis on the PACS mobility traffic between AMs and HLR by using the mobile, business, and residential subscriber profiles. In addition, four performance metrics are investigated to observe the mobility characteristics with various subscriber profiles, which include waiting times at the AM and HLR average query response times, average update response times, and the expected numbers of messages per second exchanged between the AM and HLR. Finally, some observations and comments are made for the PACS system.

A new service for digital mobile communications

We propose a new service for digital mobile communication systems which enables two or more users to hold a secure conference. Two requirements must be considered: privacy and authentication. Privacy is to ensure that an eavesdropper cannot intercept conversations. Authentication ensures that the service is not obtained fraudulently in order to avoid charge for usage. We present a new conference key distribution scheme for digital mobile communication systems. In the scheme, a group of users can generate a common secret key over the public channel to hold a secure conference.

On estimating the coverage length of toll collection area and client-server response time

The electronic toll collection system is widely applied to payment collection oo the freeway all over the world. We derive the relationship of the coverage length of the toll collection area m, the vehicle velocity v, and the mean vehicle residence time 1//spl eta/. In addition, the processing time of the client system is bounded by the factors of the mean vehicle dwell time, the propagation delay, and the transmission time. The upper bound of the server response time is calculated from the mean response time of the client system, the propagation delay, the transmission time, and the mean vehicle dwell time. Furthermore, the statistical probability bound for the response time performance of the server has been defined by the specified response time for the client system and the acceptable significance level of loss of service p in advance. Finally, the M/M/z queueing simulation estimates the number of server z required for the stringent performance requirement.

Implementation and management of a mobile phone filtering system

This paper presents the system design and network management of a mobile phone filtering system lMOFISr for filtering clones of cellular international calls by an IN-based service node approach. Copyright