Multi-channel Wireless Networks with Infrastructure Support: Capacity and Delay Hong-Ning Dai (Macau University of Science and Technology, Macau) Raymond Chi-Wing Wong (Hong Kong University of Science and Technology, Hong Kong) Qinglin Zhao (Macau University of Science and Technology, Macau) Presented by Hong-Ning Dai

Comparison with existing networks Pure Ad HocAd Hoc with Infrastructure Single Channel SC-AH networks [1] SC-IS networks [2] [3] Multiple Channels MC-AH networks [4] MC-IS networks our proposed frequency domain Ad Hoc hybridity Our proposed MC-IS networks have more benefits than the existing networks

MC-IS Network Ad hoc communications within H hops uplink downlink Infrastructure communications No capacity constraint and delay constraint within wired networks

Our contributions Formally identify an MC-IS network. Derive both the upper bounds and the constructive lower bounds of the capacity of an MC-IS network. Find that the capacity of an MC-IS network contributed by ad hoc communications is mainly limited by four requirements.

Four requirements

Summary of our major results MC-IS networks SC-IS networks MC-AH networks SC-AH networksDelayCapacityNetworks Our proposed MC-IS networks have the optimal capacity and the minimal delay!

Methodology overview Derivation of Network Capacity Contributed by Ad Hoc Communications Upper bounds Lower bounds (constructive) Derivation of Network Capacity Contributed by Infrastructure Communications Upper bounds Lower bounds (constructive) To prove these bounds is non-trivial!

Constructive lower bounds Tessellation Bound the number of interfering nodes Apply channel models (path loss, interference, shadowing) Determine the interference range The size of cell needs to be satisfied connectivity constraint with connectivity constraint Cell lattice interference constraint We must ensure the interference constraint is satisfied.

Design proper routing algorithms Connect each source destination pair S i - D i Design shorted routing path (almost straight lines) Assign the proper number of routes at each node so that (i)not too many routes (ii)not too few routes

Design TDMA scheme to schedule interfering cells to be active one by one

Other contributions Our proposed MC-IS network offers a more general theoretical framework than other existing networks. Other networks such as an SC-AH network, an MC- AH network, and an SC-IS network can be regarded as special cases of our MC-IS network.

More details about our results Ad-hoc and Sensor Networking Symposium Please refer to our paper in Proc. of IEEE International Conference on Communications (ICC) Ad-hoc and Sensor Networking Symposium More complete version: H.-N. Dai, R. C.-W. Wong, and Q. Zhao, “Multi- channel wireless networks with infrastructure support: Capacity and delay,” Tech. Rep., Feb [Online]. Available: or