Design of a Cache Management Scheme for Gateways on the Vehicular Telematics Network

A hybrid prefetch policy for the retrieval of link-associated information on vehicular networks

“…So, the design must be preceded by the specification of the target network architecture and service. This paper shares the underlying framework with Lee's work, which designed a directionbased cache management scheme [3]. Figure 1 illustrates the vehicular telematics network architecture.…”

“…Each gateway exchanges messages with vehicles while they remain in its communication range and also has reliable WAN interface through which it contacts an appropriate data service. Drivers can access the gateway and thus the global network via the in-vehicle telematics device which has computing power and a specific wireless network interface [3]. This device basically includes a GPS receiver and digital map to accommodate a bunch of location-based services.…”

“…Existing cache/ prefetch schemes for the mobile network have mainly considered the local cache within a mobile client, focusing on the k-NN (Nearest Neighbor) search [7]. However, in the telematics network, the cache is important not only for the mobile object but also for the gateway node, as almost every information is delivered through the gateway and the connection between the information server and the gateway may suffer from limited bandwidth and low throughput [3]. Based on the observation for cache management schemes, this paper addresses a hybrid prefetch scheme that combines LRU (Least Recently Used) for temporal locality and FAR (Furthest Away Replacement) for spatial locality.…”

Access pattern analysis for a directional cache scheduling scheme on vehicular telematics networks

“…The moving object must be a vehicle, whose movement is restricted to road segments. In our previous work, we proposed DW (Directional Weight) scheme for cache management policy on the gateway device [10]. It begins from the same idea of FAR.…”

“…For example, we can order the queue by the distance from the gateway to the link specified in the request, while the most basic policy is FCFS (First Come First Service). In our framework, as the DW scheme gives precedence to the direction many vehicles are heading, the angular location of the destination is important [10]. So when the request is inserted into the waiting queue, the cache scheduler sort the items according to the heading of the destination.…”