The Department
The Networking Protocols Department focuses on communications and networking protocols for wireless, wired and optical networks, and distributed computing.  Areas of research include routing, mobile ad-hoc networks, mesh networks, sensor networks, Quality of Service (QoS), including robustness and fault-tolerance, and next generation architectures for services.

Key Competencies
There are two major focus areas:

1. Wireless Ad Hoc and Sensor Networking
2. Architecture for Services, including Control and Management of Optical Networks

1. Wireless Ad Hoc and Sensor Networking
   Research Focus
   The Networking Protocols Department has built up considerable expertise in wireless multi-hop ad-hoc and mesh networks.  We have experience with the MAC protocols and physical layer characteristics of wireless technologies such as 802.11 (commonly referred to as WiFi), 802.16 (commonly referred to as WiMAX), CDMA and Ultra-WideBand (UWB).  Routing, scheduling and admission control methods and algorithms which cope with, and even take advantage of, mobility and mobile sensing nodes, in various topologies such as mesh and tree topologies, have been designed and studied.
   
   Research and development work on ad hoc and sensor networks cover several domain areas such as: (1) maritime and underwater communications and sensing, (2) monitoring and surveillance of outdoor spaces, e.g. construction site and battlefield, and (3) healthcare in the home or hospital.
   
   The high-level research objective is to develop optimized and highly survivable, integrated ad hoc and sensor networks to collect, distribute and process information to enable applications such as monitoring, surveillance and tracking.  Specific objectives in ad hoc and sensor networks research include methods and algorithms to ensure timely and reliable delivery of data to end users, to provide robust end-to-end QoS, to improve network capacity, to achieve localization, energy efficiency, and to increase coverage by clever topology management. 
   
   Going beyond the ad hoc and sensor network platform layer to the middleware and application layers, we also research on information processing methods for data fusion, estimation, tracking and behaviour recognition, such as recognition of agitation behaviour for persons with dementia.
   
   Projects
   
   • TRITON (in I²R High Speed Maritime Networks Programme):  This is a core research project that aims to develop and validate a blueprint of a highly survivable remote surveillance and communication system to enable multimedia situational awareness and command/control in ship-to-ship, ship-to-shore and underwater network applications using terrestrial wireless multi-hop networks and multi-modality mobile and static underwater nodes. Some of the research challenges include the development of robust end-to-end QoS schemes, and capacity and coverage improvement for ad hoc networks.
   • RFID SmartShelf:  This is an ETPL funded project to develop a low-cost large scale RFID system to track and locate items such as books in library applications.  This system is being explored for use by the National Library Board of Singapore.
   • UWB-based Sentient Computing, Applications and Middleware with Coordinated Quality of Service (USCAM-CQ):  This is part of an A*STAR SERC-funded research programme on UWB-enabled Sentient Computing (UWB-SC).
     
     
2. Architecture for Services, including Control and Management of Optical Networks
   Research Focus
   R&D activities on next generation service delivery platforms focuses on distributed systems with computational, content and data storage resources where performance guarantees are required in order to provide mission-critical services.
   
   In the area of optical networks, we have developed an integrated Optical Ethernet (iOPEN) architecture and a GMPLS-capable WDM optical network and distributed storage system.  These have been developed and trialed in an ongoing project known as ONFIG (Optical Network Focus Interest Group) II.   The ONFIG II test bed resembles an optical metro-access network with meshed iOPEN and GMPLS controller, high speed WDM-PON with colorless ONU, EPON and a radio-over-fiber link.
   • Optical Networking, i.e. optical network design and optimization, network management, EPON
   • Optical broadband access and Metro network architecture
   • iOPEN (integrated Optical Ethernet) architecture for efficient Metro Ethernet services
   • Optical network multiple layer protection/restoration schemes
   • Optimization and performance of optical network control and management including resource planning, routing and signaling
   • Routing and Wavelength Assignment (RWA) and survivability in optical WDM networks
   • MPLS/GMPLS

Projects

• GMPLS software development
• Development of optical design and simulation software
• Network management system for ONFIG II project

Intellectual Capital
Selected Journal Papers

• C.W. Ang and C.K. Tham, "Analysis and Optimization of Service Availability in an HA Cluster with Load-Dependent Machine Availability", IEEE Transactions on Parallel and Distributed Systems, vol. 18, no. 10, October 2007.
• D.T.C. Wong, J.W. Mark and K.C. Chua, "Video Services in a Round-Robin Carrier-Hopping Multirate Multi-Carrier DS-CDMA System," IEEE Transactions on Wireless Communications, vol. 6, no.3, March 2007, pp. 993-1002.
• K. Ratnam, L. Zhou and M. Gurusamy, "Efficient multi-layer operational strategies for survivable IP-over-WDM networks", IEEE Journal on Selected Areas in Communications (JSAC), vol.24, No.8, August 2006 page(s) 16-31.
• AC Valera, WKG Seah and SV Rao, 'Improving Protocol Robustness in Ad hoc Networks Through Cooperative Packet Caching and Shortest Multipath Routing', in IEEE Transactions on Mobile Computing, vol. 4,  no. 5,  pp. 443-457,  September/October  2005.
• P. Y. Kong and K. H. Teh, "Performance of proactive earliest due date packet scheduling in wireless networks", IEEE Transactions on Vehicular Technology, Vol. 53, No. 4, pp. 1224-1234, July 2004.

• L. Zhou, X. Shao, T.Y. Chai, C.V. Saradhi, Y. Wang, " iOPEN Network: Operation Mechanisms and Experimental Study", IEEE International Conference Communications (ICC 2007), Glasgow, UK, June 2007.
• J. Biswas et al, "Towards Ambient Intelligence for the Care of Patients in a Hospital", 5th International Conference on Smart Homes & Health Telematics (ICOST 2007), Nara, Japan, June 2007.
• H. Wang, W. K. G. Seah and P. Y. Kong, "Maximizing End-to-End Reliability of Routing with Redundant Path by Optimal Link Layer Scheduling", IEEE WCNC 2007, Hong Kong, China, March 2007.
• Lee, BH, GY Cai, G Yu and WKG Seah, "VoIP Capacity over Wireless Mesh Networks", IEEE Conference on Local Computer Networks (LCN 2006), 14-17 Nov 2006, Tampa, FL, USA. 
• Lee, HY, W.K.G. Seah and P. Sun, "Energy Implications of Clustering in Heterogeneous Wireless Sensor Networks - An Analytical View", IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'06), Helsinki, Finland, 11-14 Sept 2006.

• National Institute of Information and Communications Technology (NICT), Japanand Singapore
  • Area: maritime communications and networks
• National Library Board (NLB), ST LogiTrack
  • Area: RFID SmartShelf
• AlexandraHospital
  • Area: sensor networks for healthcare

• Ang CW, Kong PY: contribution on "opportunistic in-band sensing" in IEEE P802.22/D0.1 Draft Standard for Wireless Regional Area Networks Part 22: Cognitive Wireless RAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Policies and procedures for operation in the TV Bands, May 2006.
• Ge Y, Kong PY, Wang HG, Tham CK: contributions on "network entry process for IEEE 802.16j multihop relay networks" and "Proposal on addresses, identifiers and types of connections for 802.16j" in IEEE P802.16j Baseline Document. Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems, Multihop Relay Specification, 802.16j-06/026r3. April 2007.

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