Multi-constrained mechanism for intra-body area network quality-of-service aware routing in wireless body sensor networks

Wireless Body Sensor Networks (WBSNs) have witnessed tremendous research interests in a wide range of medical and non-medical fields. In the delaysensitive application scenarios, the critical data packets are highly delay-sensitive which require some Quality-of-Service (QoS) to reach the intended destinations. The categorization of data packets and selection of poor links may have detrimental impacts on overall performance of the network. In WBSN, various biosensors transmit the sensed data towards a destination for further analysis. However, for an efficient data transmission, it is very important to transmit the sensed data towards the base station by satisfying the QoS multi-constrained requirements of the healthcare applications in terms of least end-to-end delay and high reliability, throughput, Packet Delivery Ratio (PDR), and route stability performance. Most of the existing WBSN routing schemes consider traffic prioritization to solve the slot allocation problem. Consequently, the data transmission may face high delays, packet losses, retransmissions, lack of bandwidth, and insufficient buffer space. On the other hand, an end-to-end route is discovered either using a single or composite metric for the data transmission. Thus, it affects the delivery of the critical data through a less privileged manner. Furthermore, a conventional route repair method is considered for the reporting of broken links which does not include surrounding interference. As such, this thesis presents the Multi-constrained mechanism for Intra- Body Area Network QoS aware routing (MIQoS) with Low Latency Traffic Prioritization (LLTP), Optimized Route Discovery (ORD), and Interference Adaptive Route Repair (IARR) schemes for the healthcare application of WBSN with an objective of improving performance in terms of end-to-end delay, route stability, and throughput. The proposed LLTP scheme considers various priority queues with an optimized scheduling mechanism that dynamically identifies and prioritizes the critical data traffic in an emergency situation to enhance the critical data transmission. Consequently, this will avoid unnecessary queuing delay. The ORD scheme incorporates an improved and multi-facet routing metric, Link Quality Metric (LQM) optimizes the route selection by considering link delay, link delivery ratio, and link interference ratio. The IARR scheme identifies the links experiencing transmission issues due to channel interference and makes a coherent decision about route breakage based on the long term link performance to avoid unnecessary route discovery notifications. The simulation results verified the improved performance in terms of reducing the end-to-end delay by 29%, increasing the throughput by 22% and route stability by 26% as compared to the existing routing schemes such as TTRP, PA-AODV and standard AODV. In conclusion, MIQoS proves to be a suitable routing mechanism for a wide range of interesting applications of WBSN that require fast, reliable and multi-hop communication in heavily loaded network traffic scenarios

Performance de IEEE 802.15.6 en coexistencia con IEEE 802.15.4 e IEEE 802.11

En el presente trabajo se analiza el impacto en el rendimiento de IEEE 802.15.6 cuando es interferido por IEEE 802.15.4 o IEEE 802.11, pretendiendo dar una medida del grado de confiabilidad del primero, que es un protocolo creado para transmisión en baja potencia de parámetros vitales de pacientes humanos, cuando comparte la banda de frecuencias ISM con otros protocolos ampliamente difundidos como son los dos últimos. Las ISM son bandas de radiofrecuencia electromagnética no licenciadas, comprendidas (entre otras) desde los 2,4 a 2,5GHz1, reservadas internacionalmente para uso no comercial en áreas industrial, científica y médica. Se ha popularizado su uso en comunicaciones WiFi (distintas versiones de IEEE 802.11), Bluethoot, IEEE 802.15.6, IEEE 802.15.4, etc; pudiendo unos comportarse como ruido electromagnético de otros, especialmente en áreas densamente pobladas. A la fecha de redacción de la presente tesis, no se han encontrado trabajos donde se estudie el impacto en el rendimiento de IEEE 802.15.6 interferido por IEEE 802.15.4 o 802.11. Trabajos como el de R. Natarajan, P. Zand y M. Nabi [4] han realizado un estudio teórico y experimental de la degradación del rendimiento de IEEE 802.15.4 interferido por BLE (y viceversa) o por IEEE 802.11, pero no han considerado a IEEE 802.15.6. Otros como el de M.M Alam y E.B. Hamida compara las estrategias de coexistencia propuestas por IEEE 802.15.6 con interferencia intra-BAN, inter-BAN y degradación del canal debido al movimiento dinámico del cuerpo, pero no considera el caso en que el protocolo comparta canales con otros estándares. El presente trabajo analiza de forma teórica, repitiendo el escenario y método de R. Nataraja et al, el impacto en el rendimiento de IEEE 802.15.6 cuando es interferido por IEEE 802.11 o 802.15.4Facultad de Informátic