1 / 6

Quick Convergecast in ZigBee/IEEE 802.15.4 Tree-Based Wireless Sensor Networks

Quick Convergecast in ZigBee/IEEE 802.15.4 Tree-Based Wireless Sensor Networks. Convergecast in Zigbee/IEEE802.15.4. Zigbee/IEEE802.15.4 tree-based Wireless Sensor Network contains: One sink (Zigbee Coordinator) Some Full function devices (Zigbee Routers)

ginata
Download Presentation

Quick Convergecast in ZigBee/IEEE 802.15.4 Tree-Based Wireless Sensor Networks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Quick Convergecast in ZigBee/IEEE 802.15.4 Tree-Based Wireless Sensor Networks

  2. Convergecast in Zigbee/IEEE802.15.4 • Zigbee/IEEE802.15.4 tree-based Wireless Sensor Network contains: • One sink (Zigbee Coordinator) • Some Full function devices (Zigbee Routers) • Some reduced function devices (Zigbee end device) • Each Zigbee router is responsible for collecting sensed data from end devices associated with it and relaying incoming data to the sink.

  3. Overview of IEEE802.15.4 and Zigbee Standard • A Zigbee router can announce a beacon to start a superframe • Each superframe consists of an active portion followed by an inactive portion. • Each active portion consists of 16 equal-length slots and can further partitioned into a contention access period (CAP) and a contention free period (CFP) • CAP: Slotted CSMA/CA is used in CAP • CFP: FFDs which require fixed transmission rates can ask for guarantee time slots (GTSs) • On receiving parent router’s beacon, and end device has to wake up for an active portion to sense the environment and communication with its coordinator. • To avoid collision with its neighbor, a router should shift its active portion by a certain amount.

  4. An example of Convergecast in a ZigBee/IEEE 802.15.4 Tree-Based network

  5. Motivation • Assuming that routers relay packets in contention-free guarantee time slots (GTSs). • The collected sensory data of A in the k-th superframe can be sent to C via the GTS of C in the k-th superframe • The superframe of B in the k-th superframe appears after that of C, the collected data of B in the k-th superframe can only be relayed to C along the GTS of C in the (k+1)-th superframe. • The delay can be eliminated if the active portion of B in the k-th superframe appears before that of C

  6. Motivation and problem • The delay in not negligible because of the low duty cycle design of IEEE802.15.4. • Our goal is to solve a minimum delay beacon scheduling problemfor quick convergecast in ZigBee/IEEE 802.15.4 tree-based wireless sensor networks.

More Related