EQS: Neighbor Discovery and Rendezvous Maintenance with Extended Quorum System for Mobile Sensing Applications

Abstract

Abstract-In many mobile sensing applications devices need to discover new neighbors and maintain the rendezvous with known neighbors continuously. Due to the limited energy supply, these devices have to cycle their radios to conserve energy, making neighbor discovery and rendezvous maintenance even more challenging. To date, the main mechanism for device discover and rendezvous maintenance in existing solutions is pairwise, direct one-hop communication. We argue that such pairwise direct communication is sufficient but not necessary: there exist unnecessary active slots that can be eliminated, without affecting discovery and rendezvous. In this work, we propose a novel concept of extended quorum system, which leverages indirect discovery to further conserve energy. Specifically, we use quorum graph to capture all possible information flow paths where knowledge about known-neighbors can propagate among devices. By eliminating redundant paths, we can reduce the number of active slots significantly. Since a quorum graph can characterize arbitrary active schedules of mobile devices, our work can be broadly used to improve many existing quorumbased discovery and rendezvous solutions. The simulation and testbed experimental results show that our solution can reduce as much as 55% energy consumption with a maximal 5% increase in latency for existing solutions.

Asynchronous Neighbor Discovery on Duty-cycled Mobile Devices

“…As other related work, the studies in [28,27] propose schemes that are based upon an existing asynchronous neighbor discovery scheme to further reduce energy consumption. Two recent studies [29,12] propose neighbor discovery schemes on mobile duty-cycled devices.…”

Cost-Minimizing Mobile Access Point Deployment in Workflow-Based Mobile Sensor Networks

“…Thus, the objective is to find the assignment that minimizes the cost which is defined as (b,c,d)∈B×C×D f (b, c, d). In our CMinC problem, we set the number of time slots to be T = 3 and relax constraints (7) and (8) by setting x t i = 0 (∀i ∈ N t , ∀t ∈ {1, 2, 3}). Then, the CMinC problem formulation can be represented by the following optimization problem: min…”

“…With the advances in mobile networks, we see the emergence of mobile sensor networks [1][2][3][4][5][6][7][8] that enable flexible and wide monitoring and collection of sensory data in diverse indoor and outdoor environments. Furthermore, we observe a wide spread of mobile sensor networks, where sensing devices such as smartphones, tablets or other types of sensors are carried by robots or people (MUs) that accomplish missioncritical tasks, hence move according to predefined workflows.…”

Heterogeneous multi-channel neighbor discovery formobile sensing applications

“…The third class, proposed in [3], employs two kinds of wakeup slots, termed as anchor slots and probe slots, to achieve both lower worst-case and average discovery delay. In [21] and [22], two protocols are proposed to be implemented on top of deterministic protocols to achieve further performance gain, either in energy conservation or discovery delay. One drawback of existing deterministic protocols is the failure to support all duty cycles due to their limited choice on either prime numbers or power-multiples of the smallest duty cycles, and consequently only a limited choices of energy conservation levels can be supported.…”