Group 4 : Christopher Thorpe Jonghyun Kim ELEG-652 Principles of Parallel Computer Architectures Instructor : Dr. Gao Mentor : Joseph Data : 12/9/05

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Divide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Divide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Algorithm for a basic ray-tracing T7 T1T2 T3T4 T5 T6 Border Building Src Three types of tiles 1. Border 2. Building 3. Open space Three channel models 1. Open space 2. Absorption 3. Reflection - Devide the map by four areas - Only consider one area - Recursive algorithm

Distribution algorithm for the ray-tracing Node 0 takes care of this ray range Node 1 takes care of this ray range Node 2 takes care of this ray range Without balanced tasks Assume we use three nodes

Distribution algorithm for the ray-tracing With balanced tasks R1 R2 R3 R4 R5 R6 R7 R8 (R1+R2+R3+R4)/3 Assume we use three nodes Equal ray range for buildings is (R5+R6+R7+R8)/3 Equal ray range for borders is Each node takes care of both ray ranges

Ray direction graph When the number of rays is 200

Ray direction graph When the number of rays is 10,000

Intensity graph of the received power When the number of rays is 200

Intensity graph of the received power When the number of rays is 10,000

Test bed

Varying the size of tiles - Map area : m 2 - Number of rays : Number of nodes : 6

Varying the number of rays - Map area : m 2 - Tile size : 0.5 m - Number of nodes : 6

Varying the number of rays - Map area : m 2 - Tile size : 0.5 m - Number of nodes : 6

Varying the number of nodes - Map area : m 2 - Runtime of serial version : 231 s - Tile size : 0.2 m - Number of rays : 3000 SRC Another map

Varying the number of nodes - Map area : m 2 - Tile size : 0.2 m - Number of rays : 3000 SRC Another map

Varying the number of nodes - Map area : m 2 - Number of rays : 3000

Conclusion Performace depends on tile size, number of rays, and distribution of builings With balanced tasks, performance shows better than without balanced tasks Implementation overhead is mitigated for any practical map size.

Ray tracing - V. Sridhara, Models and Methodologies for Simulating Urban Mesh Networks - S. Bohacek, The Graph Properties of MANETs in Urban Environments - J. Hansen, Efficient Indoor Radio Channel Modeling Based on Integral Geometry raytracing/raytracing.html MPI List of references and tools