This document proposes a lightweight routing protocol called LRP-QS for wireless sensor and actor networks that provides QoS support. It divides the network into acting areas, forms a communication backbone, allows interest subscription, and uses probabilistic packet dropping and stateful updating at actors to support different data rates. A simulation study shows LRP-QS outperforms an existing protocol by having lower packet loss, control overhead, memory usage, and end-to-end delay. Future work includes improving the protocol with data aggregation, mobile nodes, and dynamic network organization.

1. Lightweight Routing with
QoS Support in
Wireless Sensor and Actor
Networks
Mustafa İlhan Akbaş and Damla Turgut
University of Central Florida
December 8, 2010

2. Problem Definition
• WSANs used in various settings
• Variance in applications → QoS
• Heterogeneous node structure → Not same as WSNs
• Objective
• Lightweight
• QoS aware routing

3. Related Work
• QBRP – QoS Based Routing Protocol for WSANs
• Similarities
• WSAN protocol
• Network organization
• Differences
• Data collection from the network
• Central processing for routing

4. Phase 1: Dividing the network
into acting areas
•Actors flood area
configuration
messages
•The sensor nodes
get their hop values
and actor IDs

5. •The network among actors
•Sink starts formation with
the area integration packet
•First transmitting neighbor
is the data destination
•The others saved in a
redundancy list
Phase 2: Formation of communication
backbone

6. Phase 3: Interest subscription
•Sink transmits the
interests via the
communication
backbone
•Actors distribute
interests in their areas
•Sensor nodes get the
interest information

7. Phase 4: Data transmission
• Packet tags: interest, rate, weight
• Tags based on local information
• The efficient rate for each interest:
𝑂𝑢𝑡𝑝𝑢𝑡 𝐶𝑎𝑝𝑎𝑐𝑖𝑡𝑦
𝑁𝑜. 𝑜𝑓 𝑎𝑐𝑡𝑖𝑣𝑒 𝑖𝑛𝑡𝑒𝑟𝑒𝑠𝑡𝑠
• FIFO queuing & probabilistic dropping at sensor
nodes
𝐷 𝑝 = 1 − 𝐶𝑠/(𝑁𝑠 ∙ 𝑅 𝑝)
𝐷 𝑝=Dropping probability, 𝐶𝑠=Shared capacity, 𝑁𝑠=Number of sharing flows
𝑅 𝑝=Rate of the packet

8. • Stateful approach for actors
• Actors estimate per-flow rate, update tags
𝑅𝑖
𝑛𝑒𝑤
=(1-𝑒−𝑇/𝐾)
𝑙
𝑇
+𝑒−𝑇/𝐾 𝑅𝑖
𝑜𝑙𝑑
where 𝑖 = interest,
𝑇= time between last two packets of 𝑖,
𝑙 = packet length
• Actors may request changes
Phase 4: Data transmission (2)

9. Example (1)
output
capacity
9
Rate: 8
Rate: 6
Rate: 2
Input Output
4
4
2
8 > 3
6 > 3
2 < 3
8 > 3.5
6 > 3.5
Black = 𝑫 𝒑= 3.5/8
Red = 𝑫 𝒑 = 3.5/6
Blue = no drop
𝟗
𝟑
= 3 𝟗−𝟐
𝟐
=3.5

10. output
capacity
10
8, w = 2
6, w = 1
2, w = 1
Input Output
5,2
2,6
2
8/2 > 2,5
6 > 2,5
2 < 2,5
8/2 > 2,6
6 > 2,6
Black = 5,2
Red = 2,6
Blue = 2
Example (2)
𝟏𝟎
𝟒
=2.5
𝟏𝟎−𝟐
𝟑
=2.6

11. Simulation Study
• OPNET
• LRP-QS vs QBRP
• Network
• Interest area: 200 m x 200 m
• No. of actor/sensor nodes: 4/60
• Sensor transmission range: 50 m
• Actor transmission range: 180 m
• Metrics
• Packet loss
• Memory consumption
• Control traffic overhead
• Delay

12. Packet loss

13. Control Overhead

14. Memory consumption

15. End-to-end delay

16. Conclusion
• LRP-QS is developed considering the
heterogeneous structure of nodes in WSAN
• LRP-QS outperforms QBRP with a lightweight
approach
• Future work
• Integrate actor placement
• Improve the performance with data aggregation
• Mobile actors and sensor nodes
• Dynamic network organization