Performance characterization and transmission schemes for instantly decodable network coding in wireless broadcast

We consider broadcasting a block of packets to multiple wireless receivers under random packet erasures using instantly decodable network coding (IDNC). The sender first broadcasts each packet uncoded once, then generates coded packets according to receivers’ feedback about their missing packets. We focus on strict IDNC (S-IDNC), where each coded packet includes at most one missing packet of every receiver. But, we will also study its relation with generalized IDNC (G-IDNC), where this condition is relaxed. We characterize two fundamental performance limits of S-IDNC: (1) the number of transmissions to complete the broadcast, which measures throughput and (2) average packet decoding delay, which measures how fast each packet is decoded at each receiver on average. We derive a closed-form expression for the expected minimum number of transmissions in terms of the number of packets and receivers and the erasure probability. We prove that it is NP-hard to minimize the average packet decoding delay of S-IDNC. We also prove that the graph models of S- and G-IDNC share the same chromatic number. Next, we design efficient S-IDNC transmission schemes and coding algorithms with full/intermittent receiver feedback. We present simulation results to corroborate the developed theory and compare our schemes with existing ones

A Proposal for Network Coding with the IEEE 802.15.6 Standard

We examine the Medium Access Control sublayer of the IEEE 802.15.6 Wireless Body Area Network (WBAN) standard, and propose minor modifications to the standard so that linear random network coding can be included to help improve energy efficiency and throughput of WBANs compatible with the standard. Both generation-based and sliding window approaches are possible, and a group-block acknowledgment scheme can be implemented by modifying block acknowledgment control type frames. Discussions on potential energy and throughput advantages of network coding are provided.Semiconductor Research Corporation. Interconnect Focus Center (Subcontract RA306-S1

Load balancing in multi-beam satellites

Tese de mestrado integrado. Engenharia Informática e Computação. Faculdade de Engenharia. Universidade do Porto. 201