A caching strategy to reduce network impacts of PCS

Abstract

We propose an auxiliary strategy, called per-user caching, for locating users who move from place to place while using Personal Communications Services (PCS). The caching strategy augments the basic location strategy proposed in existing standards such as GSM and IS-41, with the objective of reducing network signaling and database loads in exchange for increased CPU processing and memory costs. Since technology trends are driving the latter costs down, the auxiliary strategy will become increasingly attractive. The idea behind caching is to reuse the information about a called user's location for subsequent calls to that user, and is useful for those users who receive calls frequently relative to the rate at which they change registration areas. This idea attempts to explqit the spatial and temporal locality in calls received by users, similar to the idea of exploiting locality of file access in computer systems. We use a reference PCS architecture and the notion of a user's local call-to-mobility ratio (LCMR) to quantify the costs and benefits of using caching and classes of users for whom it would be beneficial. We also present two simple algorithms for estimating users' LCMR and the situation in which each is preferable. We show that under a variety of assumptions caching is likely to yield significant net benefits in terms of reduced signaling network traffic and database loads.

Performance Evaluation of Forwarding Strategies for Location Management in Mobile Networks

“…In this section, we shall parametrize our model based on the optimal hexagonal structure determined in [8] and the PCS network shown in Figure 1 as discussed in [9]. Our result enhances the previous results in [8,9] in that we allow the optimal number of forwarding steps to be determined if the forwarding and resetting technique is to be used in tracking mobile users under the same mobile environment structure and setting.…”

“…Of course, during the time period in which the pointer connection is set up, call requests can still arrive. Figure 1 shows a PCS network as discussed in [9]. Here, the home location register (HLR) and visitor location registers (VLRs) contain databases for tracking mobile users, but the intermediate switches such as regional signal transfer points (RSTPs) and local signal transfer points (LSTPs) are only used for connecting the HLR with VLRs.…”

A Comparative Cost Analysis of Degradable Location Management Algorithms in Wireless Networks

“…Thus, no explicit deregistration messages are needed so as to reduce the communication cost [18]. Figure 1 illustrates a possible hierarchical PCS network as discussed in [13]. The HLR and VLRs each contain a database for location management.…”

“…Therefore the goal is to minimize the total cost incurred in servicing location-update and calldelivery operations. For the two-tier HLR-VLR architecture, it has been separately reported that when the frequency of incoming calls is higher than the mobile user's mobility, that is when the call-to-mobility ratio (CMR) is high, the location cache scheme [13] is effective, while when CMR is low the forwarding and resetting algorithm (FRA) [14,15], the paging and location update algorithm (PLA) [16] and the local anchor algorithm (LAA) [17] are effective. There is no systematic way to categorize these location management algorithms and to compare their performance characteristics [8].…”

A unified framework for resource discovery and QoS-aware provider selection in ad hoc networks

“…Decentralized hash indexing [15,16,26]. Decentralized hash indexing has been proposed for resource discovery in peer-to-peer networks.…”