A novel memory management scheme for residential gateways

• Authors: Ibrahim Kamel;Beizhong Chen
• Venue: Information Systems Frontiers
• Year: 2009

Home gateways must manage services despite limited memory resources. In home gateway models (e.g., OSGi), services are implemented as software bundles (or plug-ins) that can be downloaded from the Internet and executed in the gateway. Services, in gateways, are not independent; they collaborate and complement each other. The problem we are solving is as follow: when the gateway runs out of memory, which service(s) will be stopped or kicked out of memory to start a new service? The problem was initially inspired by the FTTH (Fibre To The Home) trail project in Japan with NTT because of the limited memory in Panasonic set-top-box IP-STB. Note that stopping a given service means that all the services that depend on it will be stopped too. Because of the service dependencies, traditional memory management techniques, such as best fit, first fit, or worst fit, are not suitable. Our goal is to minimize the total number of stopped services while fulfilling the request of the new service. In this paper, we present two algorithms for service replacement and memory management in home gateways. The algorithms take into consideration the dependencies between different services, in addition to the amount of memory occupied by each service. The first one achieves optimal solution in O(n 2) time and O(nh) space, using dynamic programming. However, the optimal solution requires substantial memory and CPU resources. Then we propose a heuristic that compute solutions very close to the optimal but with much less time and space requirements. We carry simulation experiments to evaluate the effectiveness of the proposed techniques and compare them with traditional memory management techniques.