A Novel Scheme to Interconnect Multiple Frequency Hopping Channels into an Ad Hoc Network

Frequency hopping radios have very attractive features to be used as PAN links, but their use in ad hoc networking is problematic because of the difficulty to synchronize the channels and coordinate transmission attempts. We propose a novel mechanism to interconnect multiple frequency hopping channels into an ad hoc network based on an adapted version of CSMA/CA. The performance of the proposal is investigated using analytical and simulation tools. By using multiple channels, we achieve significant improvement in aggregate throughput despite the penalty of switching between channels. We show how this performance penalty can be decreased by grouping devices based on the traffic pattern. Keywords: ad hoc, PAN, CSMA/CA, MAC, frequency hopping, multiple channels

A Novel Scheme to Interconnect Multiple Frequency Hopping Channels into an Ad Hoc Network

this paper we suggest a new approach to interconnect multiple frequency hopping channels into an ad hoc PAN. We propose Multiple Frequency Hopping Channel communication (MFHC) to address this problem, and investigate the performance of MFHC ad hoc networks. Our approach avoids the use of a scatternet network, and allows nodes to communicate with all neighbours that are in radio range in a connection-less fashion. Our solution uses CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) random access scheme [8] for each channel, with the extension that we allow a device to switch to a new frequency hopping channel (FHC for short) before each packet transmission. Each node has an associated home FHC that it follows by default. If a source node needs to send a packet to a destination node on the same home FHC, it uses the basic random access scheme on the common hopping channel. If, on the other hand, a source node needs to send a packet to a destination node that has a different home FHC than that of the source, then it switches to the home FHC of the destination and applies the random access scheme on the destination node's home FH

Evaluating the Effectiveness of IP Hopping via an Address Routing Gateway

This thesis explores the viability of using Internet Protocol (IP) address hopping in front of a network as a defensive measure. This research presents a custom gateway-based IP hopping solution called Address Routing Gateway (ARG) that acts as a transparent IP address hopping gateway. This thesis tests the overall stability of ARG, the accuracy of its classifications, the maximum throughput it can support, and the maximum rate at which it can change IPs and still communicate reliably. This research is accomplished on a physical test network with nodes representing the types of hosts found on a typical, corporate-style network. Direct measurement is used to obtain all results for each factor level. Tests demonstrate ARG classifies traffic correctly, with no false negatives and less than a 0.15% false positive rate on average. The test environment conservatively shows this to be true as long as the IP address change interval exceeds two times the network\u27s round-trip latency; real-world deployments may allow for more frequent hopping. Results show ARG capably handles traffic of at least four megabits per second with no impact on packet loss. Fuzz testing validates the stability of ARG itself, although additional packet loss of around 23% appears when under attack