SmartBadge: An Electronic Conference Badge using RF and IR Communications

This thesis describes the design and development of the SmartBadge; an electronic replacement for the standard paper name badge worn at conferences and similar events. Both hardware and software have been designed for the SmartBadge; the hardware has been developed around a CC1010 microcontroller and RF transceiver. Attached to this are an infrared transceiver, an LCD display, some LEDs, buttons and a piezoelectric buzzer. There is also an antenna for the RF transceiver whose design is the result of SuperNEC [1] simulations. Protocol software development has focussed on the communication between a SmartBadge and other badges and base stations, yet there is still space available in the CC1010s flash memory to develop applications beyond the business card exchange example developed to demonstrate the communication software. The SmartBadge communicates with other badges by using the infrared transceiver. In the business card application a SmartBadge is worn by a person and is collecting the ID and a time counter from SmartBadges worn by other facing people as this person mingles through a conference or similar event. This data is then collected in real time using the RF transceiver to communicate with base stations which would be scattered around the venue. The RF network has been designed as a single hop network and a new Medium Access Control (MAC) protocol has been designed to allow the SmartBadges to share the links to the base stations while conserving as much energy as possible. This protocol is called Uplink MAC (or U-MAC) and is described in section 6.2

Cooperative Medium Access Mechanisms and Service-oriented Routing in Multi-hop Wireless Networks

Doktorgradsavhandling i informasjons- og kommunikasjonsteknologi, Universitetet i Agder, Grimstad, 2011Multi-hop wireless networks have been regarded as a promising path towards future wireless communication landscape. In the past decade, most related work has been performed in the context of mobile ad hoc networks. In very recent years, however, much effort has been shifted to more static networks such as wireless mesh networks and wireless sensor networks. While significant progress has been achieved through these years, both theoretically and experimentally, challenges still exist in various aspects of these networks. For instance, how to use multi-hop networks as a means for providing broadband Internet services with reliability and balanced load remains as a challenging task. As the number of end-users is increasing rapidly and more and more users are enjoying multimedia services, how to provide Quality of Service (QoS) with user satisfaction in such networks remains also as a hot topic. Meanwhile, another direction which has recently attracted lots of efforts in the international research community is the introduction of cooperative communications. Cooperative communications based on relaying nodes are capable of improving network performance in terms of increased spectral and power efficiency, extended network coverage, balanced QoS, infrastructure-less deployment, etc. Cooperation may happen at different communication layers, at the physical layer where the received signal is retransmitted and at the MAC and routing layers where a packet is forwarded to the next hop in a coordinated manner towards the destination, respectively. However, without joint consideration and design of physical layer, MAC layer and network layer, the benefit of cooperative communication cannot be exploited to the maximum extent. In addition, how to extend one-hop cooperative communication into multi-hop wireless network scenarios remains as an almost un-chartered research frontier. In this dissertation, we enhance the state of the art technologies in the field of multi-hop wireless networks from a layered perspective. While efficient scheduling mechanisms are proposed at the MAC layer, elaborate routing protocols are devised at the network layer. More specifically, by taking into account of cross layer design we cope with network congestion problems in wireless mesh networks mainly at the network layer. In order to further improve the performance of cooperative wireless networks, we propose a contention-based cooperative MAC protocol in the presence of multiple relay nodes. Since a large majority of existing cooperative MAC protocols are designed based on widely-used IEEE 802.11 MAC protocol which exhibits inherent design constraint when applied in multi-hop wireless networks, it is imperative to develop a novel cooperative MAC protocol which is appropriate for multi-hop network scenarios. Next, we propose a TDMA-based MAC protocol supporting cooperative communications in static multi-hop wireless networks. Furthermore, a cooperative lifetime maximization MAC protocol is proposed to cope with the energy hole problem in wireless sensor networks