A MANEMO node is an IP-based mobile node that has interface attachments to both a mobile network, using Network Mobility (NEMO), and a Mobile Ad Hoc Network (MANET). While communicating with a correspondent node in the Internet, the MANEMO node should use the best possible path. Therefore, as conditions change, a handover between NEMO and MANET is desirable. This paper describes the operation of a MANEMO handover when IEEE 802.11 is used. An analytical model illustrates that packet loss during a MANEMO handover may severely affect data and real-time applications. We therefore propose using buffering during the handover, by making use of the Power Save Mode in IEEE 802.11. In the proposed algorithm, a MANEMO node may rapidly switch between the two interfaces, eventually receiving packets delivered via the old network interface while initiating the Mobile IP/NEMO handover on the new interface. Performance results show that packet loss can be significantly reduced, with small and acceptable increases in signalling overhead and end-to-end delay.

Oblivious RAM is a technique for hiding the access patterns between a client and an untrusted server. However, current ORAM algorithms incur large communication or storage overhead. We propose a novel ORAM construction using a matrix logical structure for server storage where a client downloads blocks from each row, choosing the column randomly to hide the access pattern. Both a normal construction and recursive construction, where a position map normally stored on the client is also stored on the server, are presented. We show our matrix ORAM achieves constant bandwidth cost for the normal construction, uses similar storage to the existing Path ORAM, and improves open the bandwidth cost compared to Path ORAM under certain conditions in the recursive construction.