Phongsak Prasithsangaree

On indoor position location with wireless LANs

Location aware services are becoming attractive with the deployment of next generation wireless networks and broadband multimedia wireless networks especially in indoor and campus areas. To provide location aware services, obtaining the position of a user accurately is important. While it is possible to deploy additional infrastructure for this purpose, using existing communications infrastructure is preferred for cost reasons. Because of technical restrictions, location fingerprinting schemes are the most promising. In this paper we present a systematic study of the performance tradeoff and deployment issues. In this paper we present some experimental results towards such a systematic study and discuss some issues related to the indoor positioning problem.

Analysis of energy consumption of RC4 and AES algorithms in wireless LANs

Encryption algorithms are known to be computationally intensive. They consume a significant amount of computing resources such as CPU time, memory, and battery power. A wireless device, usually with very limited resources, especially battery power, is subject to the problem of energy consumption due to encryption algorithms. Designing energy efficient security protocols first requires an understanding of and data related to the energy consumption of common encryption schemes. In this paper, we provide the results of experiments with AES and RC4, two symmetric key algorithms that are commonly suggested or used in WLANs. Our results show that RC4 is more suitable for large packets and AES for small packets.

A new authentication mechanism for loosely coupled 3G-WLAN integrated networks

Recently, several authentication protocols have been proposed for wireless local area networks (WLANs) to improve security in hotspot public access and corporate networks, and some have been proposed for integrated 3G-WLAN networks. These authentication protocols are based on the extensible authentication protocol and have been directly applied to wireless networks based on their widespread use in wired networks. Depending on the 3G-WLAN architecture and how the WLAN is tied to the 3G network, these protocols could have large latency. Moreover, they do not have mechanisms for authenticating the usage time of a mobile in a WLAN. We first discuss these issues related to existing authentication protocols for a 3G-WLAN integrated network. Then, we propose a new authentication mechanism based on the dual signature concept used in secure electronic transactions that can be used in a loosely coupled architecture. Finally, we present a preliminary evaluation of the energy performance and latency of the existing and proposed protocols.

UTSAF: A Multi-Agent-Based Software Bridge for Interoperability between Distributed Military and Commercial Gaming Simulation

Rapid advances in consumer electronics have led to the anomaly that consumer off-the-shelf gaming hardware and software provide better interactive graphics than military and other specialized systems costing orders of magnitude more. UTSAF (Unreal Tournament Semi-Automated Force) is bridging software written to take advantage of the power of gaming systems by allowing them to participate in distributed simulations with military simulators. UTSAF illustrates the use of multiagent technology to flexibly interconnect otherwise incompatible systems. This article describes an architectural approach for rapidly constructing middleware by taking advantage of built-in capabilities for processing, communication, and interoperation that a multiagent infrastructure provides. Several software agents based on Reusable Environment for Task-Structured Intelligent Networked Agents (RETSINAs) are used to support interoperability between military simulation nodes based on distributed interactive simulation and Unreal game simulators. Using a multiagent system, UTSAF can be expanded to support several network environments and interact with other agent-based software.

Analysis of tradeoffs between security strength and energy savings in security protocols for WLANs

Energy sayings are extremely important in wireless networks where devices operate using battery power. Security in wireless networks is also becoming crucial with the deployment of wireless local area networks in hot spot areas, organizations, hospitals and so on. Security protocols depend on energy consuming operations that occur in the cryptographic primitives used in the protocols. It has been observed that different cryptographic algorithms consume different amounts of energy. Also, the amount of energy consumed can depend on the key size, the number of cryptographic operational rounds, and packet or frame size. At the same time, the strength of a security protocol also depends on the key sizes and ciphers used to build it. We apply these results to protocols in wireless local area networks and study the tradeoffs between the security strengths of these protocols and the amount of energy consumed. For the analysis, we use distributions of packet sizes based on packets collected in home and campus wireless local area networks and measurements of the number of CPU cycles taken for cryptographic computation.

UTSAF: a simulation bridge between OneSAF and the Unreal game engine

Rapid advances in consumer electronics have led to the anomaly that consumer off the shelf (COTS) gaming hardware and software now provide better interactive graphics than military and other specialized systems costing orders of magnitude more. UTSAF is bridging software written to take advantage of the power of gaming systems by allowing them to participate in distributed simulations with military simulators such as OneSAF which use the DIS protocol. UTSAF parses DIS PDUs and uses the information gained to control entities within the Unreal game engine using the Game-Bots modification. This paper describes the advantages of game engine based simulation and the UTSAF bridging and control architecture. Our main contribution is to build a simulation bridge that enables affordable high-quality 3-D viewers for military simulations.

UTSAF: Getting The Best of Consumer Graphics into Military Simulations

Rapid advances in consumer electronics have led to the anomaly that consumer gaming hardware and software now provide better interactive three-dimensional graphics than military and other specialized systems costing orders of magnitude more. UTSAF is bridging software written to take advantage of the power of modern gaming systems by allowing them to participate in distributed simulations with military simulators such as the Modular Semi-Automated Forces (ModSAF). UTSAF parses the ModSAF network protocol and uses the information gained to control entities within the Unreal Tournament video game, using the Gamebots modification. This paper describes the advantages of game-based simulation, and the UTSAF bridging and control architecture.

A Variation of the WTLS Authentication Protocol for Reducing Energy Consumption in Wireless Devices

Energy efficiency has been an important factor in protocol design in wireless networks where small handheld wireless devices rely solely on battery power. Security is also of great concern in wireless networks. Several security protocols adapted from wired networks have been used in wireless networks to provide identity authentication. Security protocols could contribute significantly to energy consumption, especially authentication protocols such as Wireless Transport Layer Security (WTLS) or Transport Layer Security (TLS) Handshake protocol that are based on computationally intensive public key cryptography. There have been many efforts trying to reduce cryptographic load and energy consumption at wireless devices. Some are complicated and others may not comply with existing WTLS/TLS standards. In this paper, we propose a simple variant of TLS Handshake protocol for mutual authentication and key exchange, which reduces energy consumption in wireless devices. The proposed protocol uses RSA and ECC algorithms differently to make the Handshake protocol more energy efficient. With our proposed protocol, we can save about 25% compared to 1024-bit RSA or 70% compared to 163-bit ECC Handshake protocol. Our proposed protocol can also be easily integrated into the standard WTLS protocol with small modification.