Passive monitoring is an important tool for measuring, troubleshooting, and protecting modern wireless networks. To date, WiFi monitoring has focused primarily on indoor settings or ephemeral outdoor studies though wardriving. We present Argos, the first urban-scale wireless sensor network designed explicitly to support measurement of ambient WiFi traffic across an entire city. Urban-scale wireless monitoring presents unique challenges due to limited packet-capture ability, heterogeneous traffic loads, and limited backhaul capacity between sensor nodes. Argos addresses these through in-network traffic merging and processing, plus an intelligent approach to coordinated channel sampling by multiple sniffers. Argos provides a rich query interface allowing users to study the complex dynamics of ambient wireless traffic. We present a detailed evaluation of a 26-node Argos network deployed on streetlights and rooftops around a city, demonstrating its ability to detect and classify wireless access points and clients; monitor Web page usage; detect malicious traffic; track the mobility of WiFi-equipped public transport vehicles; and fingerprint individual users through 802.11 probe request packets.

Desynchronization is a novel primitive for sensor networks: it implies that nodes perfectly interleave periodic events to occur in a round-robin schedule. This primitive can be used to evenly distribute sampling burden in a group of nodes, schedule sleep cycles, or organize a collision-free TDMA schedule for transmitting wireless messages. Here we present Desync a biologically-inspired self-maintaining algorithm for desynchronization in a single-hop network. We present (1) theoretical results showing convergence, (2) experimental results on TinyOS-based Telos sensor motes, and (3) a Desync based TDMA protocol. Desync-TDMA addresses two weaknesses of traditional TDMA: it does not require a global clock and it automatically adjusts to the number of participating nodes, so that bandwidth is always fully utilized. Experimental results show a reduction in message loss under high contention from approximately 58% to less than 1%, as well as a 25% increase in throughput over the default Telos MAC protocol.

Many telecommunication service providers (telcos) currently face new challenges of service provisioning and service activation in a multi-technology environment. The time required to develop management systems for a specific technology is always a bottleneck for the fast deployment of that technology. To be competitive in this new multi-technology environment, telcos need a flexible management system, which is technology independent and can be deployed quickly. The generic network model (GNM) (see "Generic Network Model Series", Astracon White Paper, 1998; Chen, G. and Kong, Q., "Integrated Telecommunication Management Solutions", IEEE Press, 1999) is designed to allow telecommunication networks to be modeled independently from their underlying technologies. Its purpose is to provide a vehicle for developing management applications for end-to-end connection services, across multiple technology domains. The GNM also provides a platform for better integration between different TMN (telecommunications management network) management layers, and between different management technologies. This paper presents the key components of a practical GNM based solution. It also gives a simple example of applying this solution for IP VPN services management.