SERVICE DISCOVERY BERBASIS BREADTH BLOOM FILTER DI MOBILE AD-HOC NETWORK (MANET)

Optimasi Discovery merupakan penelitian yang terus dikembangkan dalam Mobile Ad-hoc Networks (MANET) dikarenakan adanya beberapa keterbatasan dan kendala Service Discovery dalam MANET yaitu keterbatasan komputasi, keterbatasan power, keterbatasan bandwidth, tingginya mobility pada setiap node dan penentuan koordinasi node central. Dalam penelitian ini mengembangkan protokol Service Discovery di MANET yaitu optimasi paket service descriptor untuk  service request dan service advertisment dengan klasifikasi model tree/taksonomi service dan didefinisikan dengan metode Breadth Bloom Filter sehingga ukuran paket menjadi kecil. Sedangkan untuk pendistribusian paket pada layer network dengan memanfaatkan MultiPoint Relay (MPR) pada Optimized Link State Routing (OLSR). Metode pengembangan protokol Service Discovery pada penelitian ini dinamakan MY-Protokol. Untuk hasil pengujian dan analisa data dengan simulasi keberhasilan MY-Protokol dalam mengatasi kendala pada MANET yaitu pengurangan bandwidth sebesar 97% dan penurunan delay sebesar 95%

Optimisation of Mobile Communication Networks - OMCO NET

The mini conference “Optimisation of Mobile Communication Networks” focuses on advanced methods for search and optimisation applied to wireless communication networks. It is sponsored by Research & Enterprise Fund Southampton Solent University. The conference strives to widen knowledge on advanced search methods capable of optimisation of wireless communications networks. The aim is to provide a forum for exchange of recent knowledge, new ideas and trends in this progressive and challenging area. The conference will popularise new successful approaches on resolving hard tasks such as minimisation of transmit power, cooperative and optimal routing

Provision of adaptive and context-aware service discovery for the Internet of Things

The IoT concept has revolutionised the vision of the future Internet with the advent of standards such as 6LoWPAN making it feasible to extend the Internet into previously isolated environments, e.g., WSNs. The abstraction of resources as services, has opened these environments to a new plethora of potential applications. Moreover, the web service paradigm can be used to provide interoperability by offering a standard interface to interact with these services to enable WoT paradigm. However, these networks pose many challenges, in terms of limited resources, that make the adaptability of existing IP-based solutions infeasible. As traditional service discovery and selection solutions demand heavy communication and use bulky formats, which are unsuitable for these resource-constrained devices incorporating sleep cycles to save energy. Even a registry based approach exhibits burdensome traffic in maintaining the availability status of the devices. The feasible solution for service discovery and selection is instrumental to enable the wide application coverage of these networks in the future. This research project proposes, TRENDY, a new compact and adaptive registry-based SDP with context awareness for the IoT, with more emphasis given to constrained networks, e.g., 6LoWPAN It uses CoAP-based light-weight and RESTful web services to provide standard interoperable interfaces, which can be easily translated from HTTP. TRENDY's service selection mechanism collects and intelligently uses the context information to select appropriate services for user applications based on the available context information of users and services. In addition, TRENDY introduces an adaptive timer algorithm to minimise control overhead for status maintenance, which also reduces energy consumption. Its context-aware grouping technique divides the network at the application layer, by creating location-based groups. This grouping of nodes localises the control overhead and provides the base for service composition, localised aggregation and processing of data. Different grouping roles enable the resource-awareness by offering profiles with varied responsibilities, where high capability devices can implement powerful profiles to share the load of other low capability devices. Thus, it allows the productive usage of network resources. Furthermore, this research project proposes APPUB, an adaptive caching technique, that has the following benefits: it allows service hosts to share their load with the resource directory and also decreases the service invocation delay. The performance of TRENDY and its mechanisms is evaluated using an extensive number of experiments performed using emulated Tmote sky nodes in the COOJA environment. The analysis of the results validates the benefit of performance gain for all techniques. The service selection and APPUB mechanisms improve the service invocation delay considerably that, consequently, reduces the traffic in the network. The timer technique consistently achieved the lowest control overhead, which eventually decreased the energy consumption of the nodes to prolong the network lifetime. Moreover, the low traffic in dense networks decreases the service invocations delay, and makes the solution more scalable. The grouping mechanism localises the traffic, which increases the energy efficiency while improving the scalability. In summary, the experiments demonstrate the benefit of using TRENDY and its techniques in terms of increased energy efficiency and network lifetime, reduced control overhead, better scalability and optimised service invocation time

Descubrimiento de servicios cross-layer basado en OLSR para redes Manet

El auge que en los últimos años ha tenido el uso de dispositivos móviles, su integración plena en la vida de las personas, así como el desarrollo expansivo de las redes inalámbricas, y en especial de las redes MANET (Mobile Ad hoc Network), hace que actualmente sea difícil imaginar un mundo sin dispositivos inteligentes personales que nos acompañen a todas partes como, por ejemplo, los smartphones y wearables. Las redes MANET [Ahvar et al, 2007], [Tyagi et al, 2010] están compuestas por nodos móviles autónomos que se unen voluntariamente formando una red entre ellos. Son redes en las que no existe una infraestructura de red fija y la administración se realiza de forma descentralizada. Esto permite que se cree una red prácticamente de la nada, sin necesidad de intervención humana ni configuraciones previas. Los nodos que integran la red participan en la toma de decisiones, tienen su propio conjunto de protocolos de encaminamiento, en el que toman parte de forma activa y tienen mecanismos de gestión de red y procesos de intercambio de información propios. La disponibilidad de estos nodos es generalmente corta. Son nodos que entran y salen de la red sin previo aviso, con lo que la topología de la red está continuamente cambiando de forma dinámica y aleatoria. La mayoría de estos nodos son dispositivos con limitado poder de procesamiento, limitada capacidad de memoria y baja capacidad de almacenamiento de energía. Que las redes MANET sean capaces de soportar descubrimiento de servicios se antoja indispensable. Debido a la movilidad de estas redes, en cualquier momento puede cambiar la topología y los servicios y recursos que se ofrecen en la red. Los dispositivos deben poder descubrir de forma automática los servicios que están disponibles en la red, así como los nodos que proporcionan estos servicios. En esta tesis doctoral proponemos un nuevo mecanismo de descubrimiento de servicios basado en OLSR (Optimized Link State Routing Protocol) [Clausen et al, 2003] para redes MANET, que permite que de forma automática un dispositivo o nodo descubra los servicios ofrecidos por otros nodos que lo rodean. SD-OLSR (Service Discovery over OLSR) es un mecanismo que permite anunciar servicios con una sobrecarga introducida en la red pequeña, una tasa de descubrimiento de servicios alta, una tasa baja de falsos descubrimientos y un tiempo en descubrir servicios mínimo. Inicialmente definimos el mecanismo de descubrimiento de servicios sobre la primera versión del protocolo OLSR (OLSRv1). Este mecanismo ofrecía la posibilidad de que un nodo anunciara y preguntara por servicios disponibles en la red. Dadas las características proactivas del protocolo de encaminamiento OLSR vimos que no era necesario inundar la red con mensajes preguntando por servicios que los nodos ya anunciaban periódicamente. Limitar los mensajes sólo al anuncio de servicios hizo que las prestaciones del protocolo mejoraran. En abril de 2014 se estandariza la segunda versión de OLSR, OLSRv2 [Clausen et al, 2014]. Una de las líneas que manteníamos abierta era integrar y optimizar el mecanismo propuesto para OLSRv1, sobre OLSRv2, aprovechando la versatilidad y mejoras realizadas en la segunda versión del protocolo de encaminamiento. Los resultados que hemos obtenido, nos hacen pensar que SD-OLSRv2 puede ser un serio candidato para descubrir servicios en redes MANET con un número de nodos grande. Cuanto más grande es la red, más posibilidades existen de que se pierdan paquetes y en consecuencia de que los mensajes de petición de servicio que envíen los nodos, no obtengan la respuesta con el servicio solicitado. Sin embargo, los nodos en SD-OLSRv2 están continuamente anunciando servicios, con lo que las consecuencias de las posibles pérdidas de paquetes son menores. De hecho, SD-OLSRv2 ofrece una alta tasa de descubrimiento de servicios, superior al 90 %, incluso cuando los nodos se mueven a velocidades altas. La tasa de falsos descubrimientos también es pequeña, menor del 0.5 %. Además, el tiempo que tarda un nodo en descubrir un servicio es casi instantáneo, del orden de decenas de milisegundos. Y todos los nodos tienen un conocimiento global de los servicios que se ofrecen en la red al mismo tiempo.The growth that the use of mobile devices has experienced, its full integration in people's lives, as well as the expansive development of wireless networks, and especially MANET (Mobile Ad Hoc Network) networks, makes it difficult to think of a world without intelligent personal devices coming with us everywhere, as for example smartphones and wearables. MANET networks [Ahvar et al, 2007], [Tyagi et al, 2010] consist of a collection of wireless autonomous mobile nodes that join voluntarily creating a network between them. They are networks with neither fixed infrastructure requirements nor centralized management for their operation. The network nodes work together with minimal central control and human intervention. All of the nodes of these networks behave as routers and take part in discovery and maintenance of routes to other nodes in the network. They also have their own network management mechanisms and information exchanging processes. The availability of these nodes is generally short. These nodes are free to move, to join or to leave the network at any time. They move randomly and organize themselves on a random basis. This high mobility of nodes causes the network topology to change in a random and dynamic way. Most of these nodes are devices with a limited processing power, a limited memory capacity and a low capacity of energy storage. MANET networks ability to support service discovery is completely indispensable. Due to the high mobility of nodes, the topology and the services and resources offered in the network may vary. Devices must be able to discover automatically the services that are available on the network as well as the nodes that provide these services. In this doctoral thesis we propose a new service discovery mechanism based on OLSR (Optimized Link State Routing Protocol) [Clausen et al, 2003] for MANET networks which allows any device or node to automatically discover the services offered by other nodes surrounding it. SD-OLSR (Service Discovery over OLSR) is a mechanism that allows to announce services with a small network overhead, a high rate of services discovery, a low rate of false discoveries and a minimum time lapse to discover services. We first define the service discovery mechanism integrated into the first version of the OLSR (OLSRv1) protocol. This mechanism provided the possibility that a node could announce and ask for available services on the network. Given the proactive features of the OLSR proactive protocol, we saw that it was not necessary to flood up the network with messages asking for services the nodes already announced periodically. Limiting these messages only to the announcement of services made the protocol's performance improve. In April 2014 the second version of OLSR is standardized, OLSRv2 [Clausen et al, 2014]. One of the lines we kept open was integrating and optimizing the mechanism integrated into OLSRv1 on OLSRv2, taking advantage of the versatility and improvements achieved in second version of OLSR routing protocol. The results we have achieved make us believe that SD-OLSRv2 may be a serious candidate to discover services in MANET networks with big amount of nodes. The bigger the network, the bigger the chances of losing packages and, consequently, of failing to obtain the service response to the service requested by the nodes. However, the nodes in SD-OLSRv2 are continuously announcing services, therefore the consequences of the possible losses of packages are small. As a matter of fact, SD-OLSRv2 offers a high rate of service discovery, over 90%, even when the nodes are moving at a high speed. The rate of false discoveries is also small, under 0,5%. Besides, a node discovers a given service almost instantaneously, it takes it some tens of milliseconds. And every node has the global knowledge of the services being offered on the network at the same time.Programa Oficial de Posgrado en Ingeniería TelemáticaPresidente: Gabriel Macía Fernández.- Secretario: Carlos García Rubio.- Vocal: Mary Luz Mouronte Lópe