Nilesh Mishra Wake on WLAN Final WWW2006 Submissio

Wake-on-WLAN: 

Wake-on-WLAN Nilesh Mishra, Bhaskaran Raman, Abhinav Pathak Department of Computer Science and Engineering, IIT Kanpur Power management for 802.11 mesh networks using 802.15.4 Kameswari Chebrolu Department of Electrical Engineering, IIT Kanpur

802.11 Mesh Network: 

802.11 Mesh Network 802.11 designed for indoor usage Usage of 802.11 for long distance connectivity Power as a constraint Lack of support in current hardware Wake-on-WLAN • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions Summary: Current 802.11 hardware is not power efficient but is being used to provide long distance connectivity

Power Consumption Measurements: 

Power Consumption Measurements A typical mesh node Single board computer based 802.11 bridge/router Directional Antenna RF cable for connections *http://www.hyperlinktech.com/web/hg2424g.php * • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Power Consumption Measurements (continued): 

Power Consumption Measurements (continued) Observations on power consumption: Increases with insertion of card Higher for Tx than Rx Considerable variation over different card makes Summary: Even idle power consumption is significant • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Trivial solution: 

Trivial solution Node 1 Node 2 Node 3 Node 4 Wired Gateway • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Requirements: 

Requirements Node 1 Node 2 Node 3 Node 4 Wired Gateway • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

WOW!: 

WOW! Node 1 Node 2 Node 3 Node 4 Wired Gateway • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

IEEE 802.15.4: 

IEEE 802.15.4 Energy optimized Low cost radio (andlt; $5) Works in the same 2.4GHz as 802.11 Sensor motes • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Architecture: 

Architecture Node 1 Node 2 Node 3 Node 4 Wired Gateway Nodes turned off Remote turn on Multi-hop setting Delay due to boot up • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Architecture: 

Architecture RF switch or splitter Power switching circuit Node 1 Antenna Node 2 • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Implementation Details: 

CCA modes of 802.15.4 Clear if energy below threshold Clear if valid 802.15.4 packet Clear if valid 802.15.4 packet and energy below threshold Use of Chipcon’s CC2420 CCA mode Configurable frequency and energy threshold parameters Relay based switching circuit Does not store the state Implementation Details • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions Summary: 802.15.4 compliant radio is able to detect 802.11 traffic

Wake-on-WLAN Features: 

Wake-on-WLAN Features On-demand, course-grained power on/off of networking equipments at a remote site. Use of off the shelf 802.15.4 compliant sensor motes working in 2.4 GHz. Setting ideal for rural deployment. Usage of data channel itself for remote wake-up No separate antenna (shared with 802.11 equipment). • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Detection of 802.11 Transmission: 

A laptop with D-Link DWL650 802.11b card running ‘trafficgen’ application as data traffic source Packets of size 1462 bytes at 1Mbps with inter packet intervals of 10, 20 and 100ms Polling of CCA pin on sensor node every 3ms Detection of 802.11 Transmission • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions Summary: Traffic pattern of 802.11 successfully replicated on motes

Outdoor Evaluations: 

Validation on 3.5Km IITK-Mohanpur link on DGP testbed External antenna connected Calibrated 802.11 card for determining RxPower Outdoor Evaluations • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions Summary: Low sensitivity of 802.15.4 essential for working of Wake-on-WLAN in long distance settings

Example Scenario: 

Power consumption of Soekris acting as a router/switch with two wireless 802.11b cards = 7.7W (typical) Boot-up time for Soekris 50s VoIP service in Sarauhan in the DGP testbed Usage pattern: 15 calls/day of 71s avg duration Sensor mote typical values: Vcc = 2.8V and I = 23mA with CPU and Radio receiving. Example Scenario • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Example Scenario: 

Eno_wow = Pup x Tup Ewow = Emote + Ebootup + Eusage where Emote = Vmote x Imote x Tidle Ebootup = Pbootup x Tbootup Eusage = Pup x Tactive Using above values Eno_wow = 120 Whrs Emote = 1.54Whrs Ebootup = 1.04Whrs Eusage = 7.73Whrs Example Scenario Thus power saving is: (Eno_wow – Ewow)/ Eno_wow Greater than 91% • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Discussion: 

Does not work on 802.11a Hibernation facility desired: faster boot-up Suffers from noise generated triggers Advanced usage: morphing topology More detailed study of usage pattern for better power savings. Discussion • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Related Work: 

Narrow band RF detector Wake-On-Wireless [Shieh, et al] Concept of ‘smart brick’ and ‘mini brick’ Separate frequency channel for wake-up Turducken: Hierarchical power management for mobile devices [Sorber, et al] Hierarchy of devices Decomposition of task Use of WiFi detectors • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions Summary: Usage scenario for Rural Networking and use of 802.15.4 is unique Related Work

Application Scenarios: 

Application Scenarios VOIP usage in a typical setup 10-30 calls of 1-2 minutes duration Solar Power WiFi (http://www.green-wifi.org/) Low cost solar powered WiFi grid. On-demand data retrieval for bridge monitoring. • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions Summary: Wake-on-WLAN is useful in energy constrained use of 802.11 equipments

Applications: 

Applications With: Hemanth Haridas CSE, IIT Kanpur • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Application: 

Application With: Hemanth Haridas CSE, IIT Kanpur • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Application: 

Application With: Hemanth Haridas CSE, IIT Kanpur • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

New Developments: 

Signature pattern based Wake-on-WLAN Checks for a pattern in a code window Overcomes the problem of noise triggered false wake-up Works in existence of periodic or non periodic noise. Improvements in switching circuit Latching circuit Transistor based switch New Developments • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions

Conclusions: 

Lack of power save mode in current WiFi Mesh networking hardware Novel Wake-on-WLAN mechanism for multi hop remote on-demand wake-up of mesh nodes. Substantial power savings using Wake-on-WLAN (andgt; 91%). Prototype tested and verified for rural deployment Newer applications emerging. Conclusions • Introduction • Related Work • Motivation • Results • Prototype • Recent Addition • Results • Conclusions Summary: Power management tools are required for current 802.11 based networks deployed in energy constrained scenarios