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Backward Pointer

The Experts below are selected from a list of 6 Experts worldwide ranked by ideXlab platform

Asis Kumar Chattopadhyay – 1st expert on this subject based on the ideXlab platform

  • Analytical Study of a Dual Pointer Based Strategy for Location Update Using Node B Sojourn Time in UMTS Networks
    International Journal of Business Data Communications and Networking, 2018
    Co-Authors: Samir K. Sadhukhan, Chayanika Bose, Debashis Saha, Asis Kumar Chattopadhyay

    Abstract:

    This article describes how Universal Mobile Telecommunications System (UMTS) is a 3G cellular network standard that uses location update (LU) and location search (LS) for mobility management. LU requires update in two location registers (LRs) – home LR (HLR) and visiting LR (VLR) – where one HLR controls multiple VLRs. HLR updates (HLRUs) are costlier, and hence should be less frequent. To achieve it, VLRs maintain a forward Pointer chain among themselves, instead of updating HLR. But a lengthy chain increases LS cost considerably. So, we propose to restrict the chain length to unity by introducing an additional Backward Pointer, and using the concept of root-VLR similar to the home agent concept of mobile IP. We derive a closed form solution to approximate the average HLRUs per call, and substantiate it by simulation in cases of both random and diurnal mobilities. Results reveal substantial reduction in HLRUs per call, even when call-to-mobility ratio is high. UMTS operators will find the analysis worth considering, while managing their 3G networks.

Akifumi Makinouchi – 2nd expert on this subject based on the ideXlab platform

  • DANTE – Design and performance evaluation of parallel algorithms for path expressions in object database systems on NOW
    Proceedings 1999 International Symposium on Database Applications in Non-Traditional Environments (DANTE'99) (Cat. No.PR00496), 1999
    Co-Authors: Qiang Fang, Guoren Wang, Ge Yu, K. Kaneko, Akifumi Makinouchi

    Abstract:

    In OODB, path expressions are usually used for navigating through complex objects and obtaining necessary information at the far end of a sequence of object references. The parallel forward Pointer chasing algorithm (PFPC) and parallel Backward Pointer algorithm (PBPC) are natural algorithms for path expressions. If we change the implicit joins in the path expression into explicit joins, parallel join algorithms can also be employed for path expressions. In order to improve performance in a distributed environment, semi-join operations replace the join operations, which is called the parallel cascade semi-join algorithm (PCSJ). This paper mainly describes and compares PFPC and PCSJ algorithms implemented on DSVM; then analyzes the performance of algorithms from test results according to a certain benchmark. We can see PCSJ has much better performance than PFPC by the results. These parallel algorithms exploit pipelining and I/O communication parallelism; making full use of DSVM characteristics. Some valuable ideas are obtained from the theory analysis and practical testing.

Samir K. Sadhukhan – 3rd expert on this subject based on the ideXlab platform

  • Analytical Study of a Dual Pointer Based Strategy for Location Update Using Node B Sojourn Time in UMTS Networks
    International Journal of Business Data Communications and Networking, 2018
    Co-Authors: Samir K. Sadhukhan, Chayanika Bose, Debashis Saha, Asis Kumar Chattopadhyay

    Abstract:

    This article describes how Universal Mobile Telecommunications System (UMTS) is a 3G cellular network standard that uses location update (LU) and location search (LS) for mobility management. LU requires update in two location registers (LRs) – home LR (HLR) and visiting LR (VLR) – where one HLR controls multiple VLRs. HLR updates (HLRUs) are costlier, and hence should be less frequent. To achieve it, VLRs maintain a forward Pointer chain among themselves, instead of updating HLR. But a lengthy chain increases LS cost considerably. So, we propose to restrict the chain length to unity by introducing an additional Backward Pointer, and using the concept of root-VLR similar to the home agent concept of mobile IP. We derive a closed form solution to approximate the average HLRUs per call, and substantiate it by simulation in cases of both random and diurnal mobilities. Results reveal substantial reduction in HLRUs per call, even when call-to-mobility ratio is high. UMTS operators will find the analysis worth considering, while managing their 3G networks.