No abstract

In Mobile WiMAX, a Base Station (BS) delivers security keys to Mobile Stations (MSs) through a key distribution scheme to guarantee security and access control. The MSs need to perform ciphering operations to access the keys upon rekeying process. In this way, the MSs consume energy to receive and decrypt the keys for further communication with a BS, while the BS consumes energy to encrypt and transmit the keys. In current key distribution schemes, any member join or leave event results in a key updating, and the duration of the MSs stay in the cell is not important, but on average low speed MSs tend to stay longer in the cell, while fast MSs will leave the cell faster. This paper proposes an Efficient Key Distribution scheme to decrease the number of exchanged keys which results in minimizing energy consumption of the network by grouping the MSs into the different subgroups based on their speeds using complete binary tree. Analysis shows that the proposed scheme reduces energy consumption during key updating process.

In IEEE 802.16e, energy management is an important factor to be emphasized especially for Mobile Stations (MSs) due to their limitation on battery capabilities. Efficient energy scheme would guarantees long lifetime for MSs. In WiMAX service, the Base Station (BS) sends security keys to MSs using key management scheme, and MSs need to perform ciphering operations to get access to the security keys for further processing. In this way, performing high ciphering operations by MSs require more energy. This paper proposes an Efficient Key Management Scheme (EKMS) using complete binary tree structure to mitigate this issue, this is done by reducing energy consumption of MSs needed to execute key management process. Analysis shows that EKMS save energy in MSs during key management.