[Institution of Engineering and Technology International Conference on Frontiers of Communications, Networks and Applications (ICFCNA 2014 - Malaysia) - Kuala Lumpur, Malaysia (3-5 Nov. 2014)] International Conference on Frontiers of Communications, Networks and Applications (ICFCNA 2014 - Malaysia) - Spanning multi-tree algorithms for load balancing in multi-sink wireless sensor networks with heterogeneous traffic generating nodes