Meraki is a cloud-based network management system which provides centralized configuration, monitoring, and network troubleshooting tools across hundreds of thousands of sites worldwide. As part of its architecture, the Meraki system has built a database of time-series measurements of wireless link, client, and application behavior for monitoring and debugging purposes. This paper studies an anonymized subset of measurements, containing data from approximately ten thousand radio access points, tens of thousands of links, and 5.6 million clients from one-week periods in January 2014 and January 2015 to provide a deeper understanding of real-world network behavior. This paper observes the following phenomena: wireless network usage continues to grow quickly, driven most by growth in the number of devices connecting to each network. Intermediate link delivery rates are common indoors across a wide range of deployment environments. Typical access points share spectrum with dozens of nearby networks, but the presence of a network on a channel does not predict channel utilization. Most access points see 2.4 GHz channel utilization of 20% or more, with the top decile seeing greater than 50%, and the majority of the channel use contains decodable 802.11 headers.

In 2006, John Bicket and Sanjit Biswas took a leave from their graduate research at MIT to start a networking company called Meraki, which eventually grew to a fast-growing, profitable company acquired by Cisco in 2012 for $1.2 billion.

Mobile computing has deeply influenced the lives of almost every human in the world on a daily basis. In celebration of the 20th anniversary of Mobicom, Mobicom 2014 features an exciting panel on the topic of tackling societal grand challenges using mobile computing. The panel features five excellent researchers who have had a tremendous impact on the field of mobile computing over the years and whose research work has directly addressed pressing societal problems. The panel discussion will feature an in-depth discussion of the grand challenges that we face in society today and the role of mobile computing as a frontier platform for addressing these challenges. The panel will cover both a retrospective and futuristic perspective where the retrospective aspects highlight the diverse contributions of the panelists and the futuristic aspects will feature of a discussion of their individual views of what are the next big societal problems that Mobicom as a community should tackle.

This paper evaluates the ability of a wireless mesh archi-tecture to provide high performance Internet access while demanding little deployment planning or operational man-agement. The architecture considered in this paper has un-planned node placement (rather than planned topology), omni-directional antennas (rather than directional links), and multi-hop routing (rather than single-hop base stations). These design decisions contribute to ease of deployment, an important requirement for community wireless networks. However, this architecture carries the risk that lack of plan-ning might render the network's performance unusably low. For example, it might be necessary to place nodes carefully to ensure connectivity; the omni-directional antennas might provide uselessly short radio ranges; or the ine±ciency of multi-hop forwarding might leave some users e®ectively dis-connected. The paper evaluates this unplanned mesh architecture with a case study of the Roofnet 802.11b mesh network. Roofnet consists of 37 nodes spread over four square kilo-meters of an urban area. The network provides users with usable performance despite lack of planning: the average inter-node throughput is 627 kbits/second, even though the average route has three hops. The paper evaluates multiple aspects of the architecture: the e®ect of node density on connectivity and throughput; the characteristics of the links that the routing protocol elects to use; the usefulness of the highly connected mesh a®orded by omni-directional antennas for robustness and throughput; and the potential performance of a single-hop network using the same nodes as Roofnet.

This paper describes ExOR,an integrated routing and MAC protocol that increases the throughput of large unicast transfers in multi-hop wireless networks. ExOR chooses each hop of a packet's route after the transmission for that hop, so that the choice can reflect which intermediate nodes actually received the transmission. This deferred choice gives each transmission multiple opportunities to make progress. As a result ExOR can use long radio links with high loss rates, which would be avoided by traditional routing. ExOR increases a connection's throughput while using no more network capacity than traditional routine.ExOR's design faces the following challenges. The nodes that receive each packet must agree on their identities and choose one forwarder.The agreement protocol must have low overhead, but must also be robust enough that it rarely forwards a packet zero times or more than once. Finally, ExOR must choose the forwarder with the lowest remaining cost to the ultimate destination.Measurements of an implementation on a 38-node 802.11b test-bed show that ExOR increases throughput for most node pairs when compared with traditional routing. For pairs between which traditional routing uses one or two hops, ExOR's robust acknowledgments prevent unnecessary retransmissions,increasing throughput by nearly 35%. For more distant pairs, ExOR takes advantage of the choice of forwarders to provide throughput gains of a factor of two to four.

This paper analyzes the causes of packet loss in a 38-node urban multi-hop 802.11b network. The patterns and causes of loss are important in the design of routing and error-correction protocols, as well as in network planning.The paper makes the following observations. The distribution of inter-node loss rates is relatively uniform over the whole range of loss rates; there is no clear threshold separating "in range" and "out of range." Most links have relatively stable loss rates from one second to the next, though a small minority have very bursty losses at that time scale. Signal-to-noise ratio and distance have little predictive value for loss rate. The large number of links with intermediate loss rates is probably due to multi-path fading rather than attenuation or interference.The phenomena discussed here are all well-known. The contributions of this paper are an understanding of their relative importance, of how they interact, and of the implications for MAC and routing protocol design.