Applications for Mesh Networks

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [TG5 CFA Response: Applications for the Mesh Networks] Date Submitted: [01 July, 2004] Source: [ ISHIKAWA Chiaki and OKUMA Yasuyuki] Company [YRP Ubiquitous Networking Laboratory] Address [2-20-1 Nishigotanda, Shinagawa, Tokyo, 141-0031, Japan] Voice:[+81-3-5437-2270], FAX: [+81-3-5437-2271], E-Mail:[ishikawa@ubin.jp, kuma@ubin.jp] Re: [Response to IEEE P802.15.TG5 Call For Applications, Document number 15-04-0267-00-0005] Abstract: [Applications for the Mesh Networks] Purpose: [Use as one of the sets of criteria for establishing the Mesh Networks] Notice: This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

2. ISHIKAWA Chiaki OKUMA Yasuyuki YRP Ubiquitous Networking Laboratory TG5 CFA Response: Applications for Mesh Network

3. Why MESH network is needed ? (1/2) • CFA mentions and defines full and partial MESH topology and we use the definition to explain our rational below. • In view of the applications mentioned in the following, we observe that the device node for human-machine interaction (HMI) is best placed at the root of device node tree for a centralized control system. Such a node with HMI accepts human input and the control message flows from it through the tree-like partial mesh topology network. Also, the control messagesfrom such centralized controller reach the controlled node directly. (In this sense, this is more like star-topology, but generally speaking, we can have devices that can only be reached by means of hop device, e.g. across a corner wall, so general tree-like topology is definitely required.) Thus the controller is at the root of the tree and in this sense we use partial mesh, which is tree.

4. Why MESH network is needed ? (2/2) • Even in such centralized control system that uses tree-like topology for human-initiated control message flow, actuator devices and sensors within communication distance (in close proximity) should communicate with each other using full mesh topology so that we can attain optimum control of the whole system by allowing the local optimization among autonomous nodes. • For example, the medical support system mentioned in the following also can be best served by full MESH topology communication among nodes in close proximity and this is also the requirement from the application (emergency conditions of patients need to be alerted to medical staff close by). • When aggregates of nodes under control are merged or divided, we need to consider the creation of meta-MESH that consists of element subnetworks. (e.g. The hotel conference hall example in the following.). • Thus, the typical applications we consider do use and need MESH. As a matter of fact, we think that aside from the very simple sensor networks, any complex application networks that will be part of legacy application systems are highly like to require/use MESH topology.

5. Environment Control( Home control & Hall control) The environment control system considered here uses wireless personal controller which manages the device nodes embedded in lighting fixtures, air-conditioners, TVs, audio visual equipment, door locks, windows, etc.. Here we distinguish two cases based on the size of the rooms which are controlled. . + A small-scale system (e.g. home, etc.) + A large-scale system (e.g. school, office, ball rooms and conference rooms at hotels, etc.) In the latter scenario, the size of room is generally large. Also, we assume that the larger hall (conference room) is reconstructed from small halls (conference rooms) by changing partitions.

6. Security System The information from the various wireless sensors installed in a house or office are used. According to the existence and whereabout (location) of the persons, the level of security is changed automatically. Accident or intrusion by suspicious person is prevented, and safety is secured.

7. Medical support Sensors are used to monitor patient health conditions continuously. Doctors and nurses carry wireless terminals. These sensors and monitoring terminals are connected via wireless mesh network, and thus the patient information is shared among medical staff, thus resulting in safe and reliable medical care. We can avoid the initial cost of communication infrastructure by using wireless mesh network for movable instruments, fixed-location medical instruments, instruments attached to patients' beds, and terminals carried by medical staff members. We need to use secure communication (e.g. encrypted communication) so that the patient information is available only to the authorized personnel only even when we use multi-hop communication paths. We need to protect the control message in a similar manner. (Figure NEXT PAGE.)

8. Medical support : patient :patient & sensor :Doctor / Nurse & Monitor :instrument

9. Factory Assembly Line Monitoring and Control • We mention this application in passing, since this is actually very similar to medical support system mentioned in the preceding pages although superficially they look very different. • We replace the legacy monitoring and controlling systemof factory assembly line based on wire with a wireless system. • The merit of such system is the flexibility to cope with the assembly line layout. • Movable monitoring stations, fixed-location machines, terminals carried by assembly line workers and managers are all connected into MESH network. • Use of wireless communication brings about flexibility and avoids the initial layout of wire networks. • As in the medical support system application example, secure communication channel must be used to protect the sensitive monitoring information and control message.

10. Required Feature Comparison.

11. *1: Since non-IT professionals are likely to use these, it should be easy. *2: In the case of factories, it may be that adequate training is given and the ease of use may not be the utmost importance. *3: In the case of Home control system, the initial installment by professionals, and the subsequent addition of home electronic appliance ought to be handled differently. The latter should be easy for ordinary people. Required Feature Comparison. (cont’d)

12. Required Feature Comparison. (cont’d) *4 : the change of hall configuration by means of rearranging partition wall/curtain ought to be easy since this is handled by hotel personnel. *5: Halls may require longer distance, say, than home control system. *6: Considering the potential interference with medical gears, the power consumption / emission should be small! *7: for medical and factory use, the monitoring and control requires frequent data exchange. *8: control systems on the left column may be relatively simple. Medical support and factory control may require complex control and monitoring. *9: we don't want random stranger walking close-by to turn on/off devices randomly. *10: we now have added privacy issues concerning monitored data. *11: All these control application requires that they are available when needed. In medical application, it is a life-and-death issue. *12: In the control applications, the control message is likely to be distributed in a tree-like fashion. However, the sensor data are likely to be exchanged locally in a full mesh fashion. *13: sensor data is likely to be propagated to nearby doctors in a full mesh fashion. Comment *11 also applies. *14: WAN connection may be convenient, but it is not desirable due to security reasons. *15:halls/ conference rooms are re-partitioned occasionally. *16: pieces of equipment are moved to bedside or to operation rooms, and doctors carry controllers.

13. Goods Handling System (with privacy twist) • Building a MESH network using user terminals and fully functional tags attached to goods, we can track the movement of goods without much efforts on the side of the user by means of the capability to detect new node. • We can classify goods according to certain criteria easily: • We can divide the MESH into a subnet of searched goods and another subnet of other goods. • Searched goods can notify the user terminal their positional information. • If a tag is equipped with indicator device (e.g. LED), such indicator can be turned on. • When we handle goods in this manner (e.g., at make-shift delivery station, at home, etc.), we can expect such goods to be hand-carried by people. In such cases, if we can identify a tag over a period of time, we can trace the user behavior (i.e., movement). Such tracing is undesirable in security-conscious settings. We need to have a mechanism to disable such tracing. • In the case of such security-conscious application, we need a disabling function so that tags don't join MESH network automatically so that the tags people carry don't reveal information to unintended networks.