- 1 - Specialized Network Formation: Long-Thin WSNs National Chiao Tung University Department of Computer Science Yu-Chee Tseng 交通大學 / 資訊工程系 / 曾煜棋

- 2 - Introduction WSN deployment is a big concern in most practices. We propose a new long-thin (LT) topology for WSNs.  a hierarachical address assignment  much better address pool utilization Examples of LT WSNs: (bridges and roads)

- 3 - Limitations of ZigBee In ZigBee, the length of a network address is 16 bit  The maximum address capacity is 2 16 =65536 Given Cm and Rm, the depth Lm will be very restrictive  For example, given Cm=4 and Rm=2, the Lm can only no more than 14  not suitable for LT WSNs !!

- 4 - Goals (1) automatically form a LT network, (2) give addresses in a distributed manner, and (3) conduct routing Assumption:  consider only router-capable devices (ignore end devices)

- 5 - LT WSN: planning Carefully plan node placement before deploying a WSN. Divide nodes into multiple clusters.  Each cluster is as a line segment

- 6 - LT network: Role Assignment Nodes are divided into three types  Cluster head node: the first node in a line segment  Bridge node: the last node in a line segment  Normal node

- 7 - LT WSN: Logical Network After planning the network, the network manager can construct a logical network G L From G L, we can determine two parameters  CCm: the maximum number of child of a node in G L  CLm: the depth of G L GLGL CCm=2 CLm=4

- 8 - LT WSN: Hierarchical Address Pool Divided address into two parts:  Cluster ID  assigned to nodes of G L : similar the orignial ZigBee scheme  Node ID  assign to cluster members: according to their hop counts to the cluster head Challenge: how to perform this automatically  a distributed node ranking scheme

- 9 - Contributions The first work that promotes the long-thin topology for WSN Propose a network formation protocol for LT WSN Propose a routing scheme suitable for LT WSN (omitted here) Reference:  M.-S. Pan, H.-W. Fang, Y.-C. Liu, and Y.-C. Tseng, "Address Assignment and Routing Schemes for ZigBee- Based Long-Thin Wireless Sensor Networks", IEEE VTC, 2008-Spring.