Searchlight: Won't you be my neighbor?

Mehedi Bakht, Matt Trower, Robin Kravets

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The rapid deployment of millions of mobile sensors and smartphones has resulted in a demand for opportunistic encounterbased networking to support mobile social networking applications and proximity-based gaming. However, the success of these emerging networks is limited by the lack of effective and energy efficient neighbor discovery protocols. While probabilistic approaches perform well for the average case, they exhibit long tails resulting in high upper bounds on neighbor discovery time. Recent deterministic protocols, which allow nodes to wake up at specific timeslots according to a particular pattern, improve on the worst case bound, but do so by sacrificing average case performance. In response to these limitations, we have designed Searchlight, a highly effective asynchronous discovery protocol that is built on three basic ideas. First, it leverages the constant offset between periodic awake slots to design a simple probingbased approach to ensure discovery. Second, it allows awake slots to cover larger sections of time, which ultimately reduces total awake time drastically. Finally, Searchlight has the option to employ probabilistic techniques with its deterministic approach that can considerably improve its performance in the average case when all nodes have the same duty cycle. We validate Searchlight through analysis and realworld experiments on smartphones that show considerable improvement (up to 50%) in worst-case discovery latency over existing approaches in almost all cases, irrespective of duty cycle symmetry.

Original languageEnglish (US)
Title of host publicationMobiCom'12 - Proceedings of the 18th Annual International Conference on Mobile Computing and Networking
Number of pages12
StatePublished - 2012
Event18th Annual International Conference on Mobile Computing and Networking, MobiCom 2012 - Istanbul, Turkey
Duration: Aug 22 2012Aug 26 2012

Publication series

NameProceedings of the Annual International Conference on Mobile Computing and Networking, MOBICOM


Other18th Annual International Conference on Mobile Computing and Networking, MobiCom 2012


  • Ad-hoc networks
  • Mobile social networks
  • Neighbor discovery
  • Smartphone

ASJC Scopus subject areas

  • Software
  • Hardware and Architecture
  • Computer Networks and Communications


Dive into the research topics of 'Searchlight: Won't you be my neighbor?'. Together they form a unique fingerprint.

Cite this