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Analytical model optimizing TDMA parameters based on network conditions for energy efficiency and capacity improvement. Explores soft clustering, dropped packets, collisions, and proof of concept to enhance multi-hop time reservation. Overcomes simulation shortcomings for scalability and accuracy, providing insights for upper layer integration. Future work includes energy consumption optimization and PHY layer enhancements. Contact for more info.
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Adaptation of TDMA Parameters Based onNetwork Conditions Bora Karaoglu Tolga Numanoglu Wendi Heinzelman Department of Electrical and Computer Engineering University of Rochester, NY, USA
Motivation Capacity Each tx occupies some part of the capacity
Motivation Clustering approach: Divide into a number of chunks CHs use chunks Question? How many chunks? Work summarized in: Analytical model Optimization
Agenda Protocol Overview: MH-TRACE Analytical Model Dropped Packets Collisions Proof of Concept Optimization of TDMA parameters
Multi-Hop Time Reservation Using Adaptive Control for Energy Efficiency • TDMA • Soft clustering • CHs responsible for channel access only • Inter cluster communication is allowed Nf = 6
Protocol Overview: MH-TRACE Factors limiting performance: Dropped Packets Real-time communication Limited Local Capacity Clustering Uneven distribution of Load Node Distributions Mobility Collisions Spatial Reuse Limited capacity Divisions
Agenda Protocol Overview Analytical Model Dropped Packets Collisions Proof of Concept Optimization of TDMA parameters
Analytical Model • Shortcomings of Simulations • Substantial Processing Power and Time • Repetitions for statistical accuracy • Valid only for the parameters set used • Scalability of Simulation Area • Edge Effects
Dropped Packets Probability of Dropping a Packet Capacity per Cluster: Number of Data Slot per Frame Nonlinear relation between Load and Pdp Detailed probability distribution of Load is needed
Dropped Packets Ps:Ratio of number of nodes in spurt to all nodes Voice Activity Detector NCH:Number of CHs each node can receive access from NCM:Number of nodes in the Cluster
Dropped Packets Effect of Dropped Packets on Throughput Considering Rx Throughput Each node all one hop neighbors
Collisions Number of frames (Nf) vs. co-frame CH separation (dch) Labeling structure used in cellular systems Co-frame CH separation (dch) vs. number of collisions (fcoll) Correlation between Number of Nodes that can cause collisions Number of Collisions
Agenda Soft Clustering Approaches Protocol Overview Analytical Model Dropped Packets Collisions Proof of Concept Optimization of TDMA parameters
Proof of Concept Number of Packets Lost per Superframe (Nf = 6)
Proof of Concept Number of Packets Lost per Superframe (Nf = 8)
Agenda Protocol Overview Analytical Model Dropped Packets Collisions Proof of Concept Optimization of TDMA parameters
Optimization of TDMA parameters • optimization with corresponding throughput figures with respect to the maximum realizable throughput Theoretically OptimizedNf
Conclusions and Future Work The model Accurate Can be used in optimization of parameters Instantaneous results for changing Transmission Power Propagation Model PHY Specs: Freq, Threshold values … Asymptotic behavior Energy consumption Average node sleep/awake durations Average energy consumption per node Node and CH comparison wrt energy consumption Optimization of Nf wrt energy consumption We are going to add effects of upper layers into the model
Thanks! Questions&Comments? Contact Info: Web : www.ece.rochester.edu/~karaoglu/ E-mail : karaoglu@ece.rochester.edu
PHY Layer Abstraction • BW • Each tx occupies some part of the BW • Transmissions should overcome any noise present in the space of the BW • Divide • Spatial reuse
PHY Layer Abstraction • TDMA: • Divide BW along time axis • Clustering: • Distribute parts of BW spatially among clusters
Protocol Overview TDMA Soft Clustering CHs responsible for channel access only Inter cluster communication is allowed
Analytical Analysis Shortcomings of Simulations Substantial Processing Power and Time Repetitions for statistical accuracy Valid only for the parameters set used Scalability of Simulation Area Edge Effects
Analytical Analysis Factors limiting performance: Dropped Packets Real-time communication Limited Local Capacity Clustering Uneven distribution of Load Node Distributions Mobility Collisions Spatial Reuse Limited BW Divisions
Dropped Packets Probability of Dropping a Packet Capacity per Cluster: Number of Data Slot per Frame Nonlinear relation between Load and Pdp Detailed probability distribution of Load is needed
Dropped Packets ps:Probability of a node to be in spurt duration pA:Probability of a node to be in the communication range of a CH pd:Probability of a node that is in the communication range of a CH to choose that CH as its channel access provider Independent of Node Density assumed constant
Dropped Packets ps:Probability of a node to be in spurt duration pA:Probability of a node to be in the communication range of a CH pd:Probability of a node that is in the communication range of a CH to choose that CH as its channel access provider pdn = ps pA pd
Collisions Number of frames (Nf) vs. co-frame CH separation(dch) Labeling structure used in cellular systems
Collisions co-frame CH separation (dch) vs. number of collisions (fcoll)
Collisions co-frame CH separation (dch) vs. number of collisions (fcoll) • NnCH: Expected number of nodes in the cluster • Nn: Total number of nodes • NC : Number of cluster in 2*rcomm range • V : Region bounded by the circle with radius 2*rcomm around origin • fcoll : number of packets lost per SF due to collision
Agenda Soft Clustering Approaches Protocol Overview Analytical Analysis Dropped Packets Collisions Proof of Concept Optimization of TDMA parameters
Proof of Concept Total Number of Packets Lost per Superframe
Proof of Concept RX Throughput per Superframe
Agenda Soft Clustering Approaches Protocol Overview Analytical Analysis Dropped Packets Collisions Proof of Concept Optimization of TDMA parameters
Other Uses of the Model Instantaneous Analysis Results for changing Transmission Power Propagation Model PHY Specs: Freq, Threshold values … Asymptotic Behavior Energy Consumption Average node sleep/awake durations Average energy consumption per node Node and CH comparison wrt energy consumption Optimization of Nf wrt energy consumption
Thanks! Questions&Comments?