Analyzing Metropolitan-Area Networking within Public Transportation Systems for Smart City Applications

Torsten Zimmermann, Hanno Wirtz, Oscar Punal, Klaus Wehrle
2014 2014 6th International Conference on New Technologies, Mobility and Security (NTMS)  
In the scope of smart cities, mobile participatory sensing and metropolitan area networking on top of public transportation systems for communication offers widespread dissemination of information in both time and spatial domains. Specifically, the transportation network naturally reflects urban human mobility patterns between places of interest and interconnects hotspots where information is created and consumed by citywide applications. Previous work has targeted communication exclusively
more » ... een users of the public transportation system. In this paper, we provide an analysis of metropolitan networking within the transportation system itself. Instead of relying on user-generated contact traces purely between mobile entities, i.e., busses, we build on a comprehensive data set that contains the schedules and location data of busses as well as the location of infrastructure elements, such as bus stops. Our analysis shows the general feasibility of such a network as well as the, previously not considered, impact of infrastructure elements for information dissemination. The latter motivates delay-tolerant and locationdriven communication, as well as participatory sensing using the transport system as a communication infrastructure. wireless advertisements, social networking, and image sharing. Moreover, users may exploit the quasi-deterministic mobility patterns to address messages to specific locations. Within the city, messages then may have semantic meaning only at their target locations, for example a lecture announcement on campus. Additionally, mobile elements can be equipped with sensors that record noise and air quality, among others. The collected information enables Participatory Sensing and Data Collection applications on a metropolitan scale [5] . We argue that communication on top of transportation networks provides a contribution to smart city scenarios. In this, the resulting communication network allows capturing phenomena on the fly and in an integrated fashion, thus "capturing the pulse of the city". In addition, reusing the existing infrastructure of the transportation systems mitigates the need for dedicated deployments, reducing capital and operating expenditures. In this paper, we analyze the feasibility of establishing a communication network within the transportation system, i.e., comprehensively utilizing the infrastructure, mobile elements, and domain knowledge as provided by the transportation system operator. We extend existing analytical efforts that sketch communication networks on top of transportation systems [6] or within synthetic traces [7] . Conversely, we propose wireless communication between the vehicular mobile elements as well as with infrastructure such as bus stops. Providing (open) 802.11 wireless network access at and through both these element types opens the network up for user communication and involvement, resulting in a city-wide store-and-forward network that facilitates a variety of applications. A. Existing Work Utilizing contacts between mobile transportation entities for communication offers a promising venue of establishing a mobile communication network. In this section, we thus delimit our contribution from existing works. In DieselNet [1], the authors leverage a bus transportation network serving the UMass Amherst campus to establish a DTN. Deriving mobility and contact traces from their findings, the authors analyze the number and duration of bus contacts. RUTS [6] proposes a delay tolerant forwarding mechanism that takes the characteristics of urban transport systems into account. In this, the authors focus on exploiting the transportation system for message forwarding between DTN users. The approach is evaluated using synthetically generated bus traces superimposed onto OpenStreetMap (OSM) cartographical material within an opportunistic networking simulator environment 1 . In a similar approach [2], the same authors incorporate trace data from the Chicago Transport Authority (CTA) Bus Tracker API 2 . An analysis of the trace data reveals the cyclic nature of the underlying transportation network. However, no analysis of this real-world setting for communication is provided. We differ from the aforementioned works in that we strive to integrate the transportation system, and the resulting communication network, into the operation of a smart city. We 1
doi:10.1109/ntms.2014.6814007 dblp:conf/ntms/ZimmermannWPW14 fatcat:hn22xlld5bgibbghd4nlwjtdhm