This paper presents a geographic routing protocol, boundary state routing (BSR), which consists of two components. The first is an improved forwarding strategy, greedy-bounded compass, which can forward packets around concave boundaries, where the packet moves away from the destination without looping. The second component is a boundary mapping protocol (BMP), which is used to maintain link state information for boundaries containing concave vertices. The proposed forwarding strategy greedy-bounded compass is shown to produce a higher rate of path completion than Greedy forwarding and significantly improves the performance of greedy perimeter state routing (GPSR) in sparse networks when used in place of greedy forwarding. The proposed geographic routing protocol BSR is shown to produce significant improvements in performance in comparison to GPSR in sparse networks due to informed decisions regarding the direction of boundary traversal at local minima.

Array processing is applied to signals arising in seismology, sonar, radar, astronomy and remote sensing. Optimal filtering of the sensor signals utilises the spatial diversity of the array receivers so that a desired signal embedded in coherent noise signals and random noise may be extracted. This paper provides an analytic solution for the optimal array filter for the case where the desired wide-band signal is all-pass filtered and a single coherent interference is nulled. The filter coefficients are computed without matrix inversion and the solutions take the form of rational polynomials with a common denominator term that can be interpreted in terms of a spatial sampling requirement. As the OAF has an all-pass response with minimum delay for the desired output signal, the array filter structure is seen to be a standard signal summer followed by a post-interference canceller (PIC).>