ICEDB: Intermittently-Connected Continuous Query Processing

Abstract

Several emerging wireless sensor network applications must cope with a combination of node mobility (e.g., sensors on moving cars) and high data rates (media-rich sensors capturing videos, images, sounds, etc.). Due to their mobility, these sensor networks display intermittent and variable network connectivity, and often have to deliver large quantities of data relative to the bandwidth available during periods of connectivity. Unfortunately, existing distributed data management and stream processing are not appropriate for such applications because they assume that the network connecting nodes in the data processor is "always on," and that the absence of a network connection is a fault that needs to be masked to avoid failure. This thesis describes ICEDB (Intermittently Connected Embedded Database), a continuous query processing system for intermittently connected mobile sensor networks. ICEDB incorporates two key ideas: (1) a delay-tolerant continuous query processor, coordinated by a central server and distributed across the mobile nodes, and (2) algorithms for prioritizing certain query results to improve application-defined "utility" metrics. We describe the results of several experiments that use data collected from a deployed fleet of cabs driving in Boston.

Multimedia traffic information in vehicular networks

“…This is a significant advantage over a cloud-computing solution such as ICEDB [6]. Furthermore, considering that a large city has millions of vehicles, a central-server solution will also have problems of bandwidth and performance.…”

“…To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific permission and/or a fee. ACM GIS '09 , November [4][5][6]2009. Seattle, WA, USA (c) 2009 ACM ISBN 978-1-60558-649-6/09/11...$10.00 communication (i.e., hybrid).…”

Event-Based Location Dependent Data Services in Mobile WSNs

“…However, these approaches either lack the in-network optimization [17,19] or introduce additional overhead in query processing through maintaining a partial map of the network [15] and informing all the network nodes of the aggregate query result [16]. Moreover, their system models and query types are different from ours.…”

“…Recently, mobile sensors are introduced into the Wireless Sensor Networks (WSNs) to provide various data services in many applications [15,16,17,18]. However, location dependent data service queries whose results depend on the current locations of the target mobile sensors still cannot be efficiently answered by existing approaches.…”

“…Some recent work starts to address sensor mobility for query processing in mobile WSNs such as CNFS [15], CountTorrent [16], ICEDB [17] and MobiQuery [19]. However, these approaches either lack the in-network optimization [17,19] or introduce additional overhead in query processing through maintaining a partial map of the network [15] and informing all the network nodes of the aggregate query result [16].…”