Routing Stability in Static Wireless Mesh Networks

Considerable research has focused on the design of routing protocols for wireless mesh networks. Yet, little is understood about the stability of routes in such networks. This understanding is important in the design of wireless routing protocols, and in network planning and management. In this paper, we present results from our measurement-based characterization of routing stability in two network deployments, the UCSB MeshNet and the MIT Roofnet. To conduct these case studies, we use detailed link quality information collected over several days from each of these networks. Using this information, we investigate routing stability in terms of route-level characteristics, such as prevalence, persistence and flapping. Our key findings are the following: wireless routes are weakly dominated by a single route; dominant routes are extremely short-lived due to excessive route flapping; and simple stabilization techniques, such as hysteresis thresholds, can provide a significant improvement in route persistence.

Publication

Krishna Ramachandran, Irfan Sheriff, Elizabeth Belding, Kevin Almeroth, Routing Stability in Static Wireless Mesh Networks, Passive and Active Measurement Conference, Louvain-la-neuve, Belgium, April 2007.

Data sets

The paper indexed above describes in detail the methodology used to collect the datasets.

The datasets are provided for each minute between the times indicated in the filename. For each minute, the neighbortable indicates the neighbors of each radio in the testbed along with each neighbor's ETT value. ETT is the estimated time to transmit a packet on a link to a neighbor.

For the UCSB dataset, autorate was used. Therefore only one ETT value is indicated corresponding to the automatically decided rate. For the MIT dataset, however, probes were sent at each data rate. Hence, a neighbortable for each data rate exists.

The Perl script utot is a handy tool to convert a unix time stamp to human readable time. An example invocation is utot 1143927049, which yields Sat Apr 1 13:30:49 2006.

UCSB Data Set

ucsb_meshnet_nodes contains the IP addresses of nodes in the UCSB MeshNet that participated in the experiment. The file format is fairly self-explanatory. The boolean_defaul_band_radio field can be ignored.

1143927049-1143953729.tar.gz: This data set was collected on April 1, 2006 between 13:30:49 to 20:55:29.
1144373273-1144393193.tar.gz: This data set was collected on April 6, 2006 between 18:27:53 to 23:59:53.
1144393236-1144450070.tar.gz: This data set was collected on April 7, 2006 between 00:00:36 to 15:47:50.

MIT Data Set

mit_roofnet_nodes contains the IP addresses of nodes in the MIT Roofnet along with each node's coordinates.

nt-May19-May22.tar.gz: This data set contains neighbortables for each 802.11b data rate for each minute from May 19th, 2004 to May 22, 2004. This particular dataset is a smaller sanitized subset of traces contained at the MIT Roofnet project page.



Contact: Krishna Ramachandran if you have any questions.
This work is currently supported in part by the National Science Foundation and Intel. Any opinions, findings, and conclusions or recommendations expressed in these materials are those of the author(s) and do not necessarily reflect the views of any of these organizations. We are very grateful to our sponsors - thank you!!!