Dynamic Cache Invalidation in Wireless Environments

Abstract

In this era of Internet and its related technologies such as 4G, and 5G, there is a need of fast response time for various queries raised by intermediate nodes and mobile terminals (MTs) from infra structured-based/less networks. Although there has been many e orts in the past to address this issue by using an Invalidation Report (IR)- based cache management schemes which reduce the bandwidth requirements and bat- tery consumptions but, for high update rate on server, most of the existing approaches have long query latency due to large and xed size of IRs, and broadcast time (BT) interval. In all such cases, IRs become unmanageable due to the poor utilization of available bandwidth and non-adaptive size of IRs. So, to address these issues, in this thesis, various cache invalidation techniques are proposed. In the proposed work, two types of environments are considered for validation of designed techniques. One is wireless environment without gateway cooperation and another is Internet based vehicular environment with cooperation from gateways. In wireless environment without gateway cooperation, an adaptive Cache inval- idation technique (ACIT) is proposed. In comparison to the previous approaches, the proposed scheme uses di erent threshold update rates for adaptive IR, and BT intervals. In the proposed scheme, only hot data updates in IR are recorded which re- sults a less query delay and bandwidth consumption. The performance of the proposed ACIT scheme is studied in wireless environment by extensive simulations with respect to various metrics such as Average Query Response Time (AQRT), IR size, Number of Uplink Requests, and BT by varying update and query rates. The performance of the proposed scheme is evaluated by comparing it with other state-of-the-art schemes such as Update Invalidation Report (UIR) and Selective Adaptive Sorted (SAS). The results obtained shows that the proposed scheme is better than the existing schemes.