Link-level Measurements from an b Mesh Network Dainel Aguyo, John Bicket,Sanjit Biswas, Glenn Judd, Robert Morris M.I.T, CMU

Abstract Roofnet を使用して、実際に MANET を 構築 Roofnet を使用して、実際に MANET を 構築 ロスの解析を行なう ロスの解析を行なう

Roofnet

Roofnet

Distribution of Delivery Probabilities Links with intermediate loss rates are common, with no sharp transition between high and low packet loss rates. Links with intermediate loss rates are common, with no sharp transition between high and low packet loss rates.

Spatial Distribution of Loss Rate Inter-node distance is not strongly correlated with whether nodes can communicates. Inter-node distance is not strongly correlated with whether nodes can communicates.

Time Variation of Loss Rate Most links have non-bursty loss patterns. Most links have non-bursty loss patterns.

Effect of Signal-to-Noise Ratio Links with very high signal strengths are likely to have low loss rates, but in general signal strength has little predictive value. Links with very high signal strengths are likely to have low loss rates, but in general signal strength has little predictive value.

Effect of Transmit Bit-rate A link is likely to have a significant loss rate at its optimum b bit-rate. A link is likely to have a significant loss rate at its optimum b bit-rate.

Effect of Multi-path Mutil-path fading greatly affects outdoor links and helps explain intermediate loss rates Mutil-path fading greatly affects outdoor links and helps explain intermediate loss rates

Comparison of Routing Metrics for Static Multi-Hop Wireless Networks Richard Draves, Jitendra Padhy, Brian Zill Microsoft Research

Abstract DSR like の MANET プロトコルを実装し て、 Path Metric の違いによる、性能評 価を行なう。 DSR like の MANET プロトコルを実装し て、 Path Metric の違いによる、性能評 価を行なう。 Metric – ETX, Per-hop RTT, per-hop packet pair, minimum-hop Metric – ETX, Per-hop RTT, per-hop packet pair, minimum-hop

Link Quality Metrics Hop Count: shortest-path routing Hop Count: shortest-path routing RTT: round-trip time latency RTT: round-trip time latency PktPair: packet-pair latency PktPair: packet-pair latency ETX: expected transmission count ETX: expected transmission count

Ad Hoc Routing Architecture DSR + support link quality metric （ Link-Quality Source Routing) DSR + support link quality metric （ Link-Quality Source Routing) Supports IPv4, IPv6 etc unmodified Supports IPv4, IPv6 etc unmodified Supports multiple link technologies Supports multiple link technologies Ethernet Mesh Connectivity Layer (with LQSR) IPv4IPv6IPX

Impact of Long Lived TCP Flows Route Flapping のため、 RTT ・ PktPair は 性能が良くない Route Flapping のため、 RTT ・ PktPair は 性能が良くない

Impact of Path Length EXT は shortest hop より、 hop 数の多い 経路を使用している EXT は shortest hop より、 hop 数の多い 経路を使用している

Impact of Path Length(Cont.)

Multiple Simultaneous TCP Transfer pktpair は ホップ数が増えるほど低下 pktpair は ホップ数が増えるほど低下

Web-like TCP Transfers Hop 数が長いと、 ETX のほうが HOP に比 べ性能がよい Hop 数が長いと、 ETX のほうが HOP に比 べ性能がよい

A Mobile Scenario ETX ではノードの移動による経路品質 の変化に対し、適応できない ETX ではノードの移動による経路品質 の変化に対し、適応できない