1. Mechanisms in Support of Real-Time Mesh Deployment
May 2007
doc.: IEEE /0297r1
May 2007
Mechanisms in Support of Real-Time Mesh Deployment
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Michael Souryal, NIST
Michael Souryal, NIST

2. May 2007
doc.: IEEE /0297r1
May 2007
Abstract
This presentation discusses mechanisms that could be useful in support of real-time deployment of a multihop mesh network.
Michael Souryal, NIST
Michael Souryal, NIST

3. Applications: Public Safety/Military
May 2007
Applications: Public Safety/Military
Emergency response, no infrastructure in place
Urban Search & Rescue (US&R) operations involving robots
Coal mine rescue operations
Communications and clearing operations in caves and tunnels
Urban fighting scenarios, …
Common Need
Rapid deployment of multihop/mesh infrastructure
Michael Souryal, NIST

4. Excerpts from IEEE 802.11 TGs Usage Models (11-04/662r16)
May 2007
Excerpts from IEEE TGs Usage Models (11-04/662r16)
From Description of Public Safety Usage Model
“Communications for public safety networks are mostly outdoors, but may include communicating with first responders inside buildings (potentially deep inside with contact only by multi-hop relaying).... Node mobility, dynamic variations in radio propagation, equipment/power failures, etc. make network self-configuration and self-management essential in these scenarios.”
From Usage Model Characteristics Table
Usage Model Category
Mesh AP/ Point Mobility
Public Safety
Mix of fixed radios (e.g. on poll tops) and mobile nodes deployed in emergency vehicles and carried by emergency workers.
Military
May have a few stationary radios … and mobile nodes deployed in combat vehicles, ships or carried by dismounted troops.
Michael Souryal, NIST

5. Potential Emergency Response Usage Scenario
May 2007
Potential Emergency Response Usage Scenario
Extend signal coverage through a multihop network that relays data/voice between first responders and Incident Command (IC)
“Breadcrumb” relays ( ) are dropped at appropriate points along path into a building
Michael Souryal, NIST

6. Objectives of Rapid Mesh Deployment
May 2007
Objectives of Rapid Mesh Deployment
Maintain network connectivity
Existence of a multihop path between any two mesh points
Permit reliable end-to-end communications
Adapt to changing environmental conditions
Potential Mechanisms
Rapid link quality measurement
Path (route) diversity
Adaptive path selection (routing)
Power control
Michael Souryal, NIST

7. Example Use of Link Quality Measurement in Rapid Mesh Deployment
May 2007
Example Use of Link Quality Measurement in Rapid Mesh Deployment
Mobile MP
“Incident Command”
Measurement Requests
Measurement Responses
Deployed MPs
Mobile MP probes channel every  sec.
Measures link quality of each measurement response
If filtered measurements of a critical number of links are less than a threshold, trigger deployment of a new MP.
Avg. RSS
Time
Sth
Deployment triggered
Michael Souryal, NIST

8. Link Measurement Request/Report
May 2007
Link Measurement Request/Report
based on P802.11k/D7.0 (January 2007)
Link Measurement Request Frame
Tx Power
Max Tx Power MP MP
Link Measurement Report Frame
TPC Report Element,
…, RCPI, RSNI
RCPI: Received channel power indicator
RSNI: Received signal to noise indicator
Michael Souryal, NIST

9. May 2007
Sample Data: Bi-directional Filtered SNR Measurements of a Symmetric Mobile Link
Fixed STA “A”, mobile STA “B”
“B” carried down 110 m corridor and back at ~ 1.2 m/s
Sampling period: 100 ms
Filter: Uniform moving average of last 20 samples (2 s filter)
Data rate: 2 Mbps
Michael Souryal, NIST

10. May 2007
Sample Data: Bi-directional Filtered SNR Measurements of an Asymmetric Mobile Link
Fixed STA “A”, mobile STA “B”
“B” carried down 110 m corridor and back at ~ 1.2 m/s
Sampling period: 100 ms
Filter: Uniform moving average of last 20 samples (2 s filter)
Data rate: 2 Mbps
Michael Souryal, NIST

11. Summary and Recommendations
May 2007
Summary and Recommendations
Rapid deployment of evolving mesh networks (e.g., TGS public safety and military usage models) requires a collection of mechanisms some of which lie outside the scope of existing task groups.
We propose the establishment of an Interest Group to gauge the level of interest in developing best practices for certain aspects of rapid network deployment, such as real-time link quality measurement, deployment algorithms, and power control mechanisms. Can lead to the development of a Study Group.
Michael Souryal, NIST

12. May 2007
Appendix
Michael Souryal, NIST

13. Deployment Algorithm Tradeoffs
May 2007
Deployment Algorithm Tradeoffs
 × N = 4 sec
Filter length (N)
Post-deployment RSS – Sth (dB)
 = 100 ms
Post-deployment RSS – Sth (dB)
Probe period, filter length (, N)
Deployment Parameters 
Probe period N
Averaging filter length
Sth
Threshold RSS
Michael Souryal, NIST

14. May 2007
References
IEEE P /662r16, “IEEE TGs Usage Models,” W. Steven Conner, January 18, 2005.
IEEE P802.11k/D7.0, “Radio Resource Measurement,” January 2007.
Michael Souryal, NIST