Innovation symbol systems: Multimodal grammars and vocabularies for facilitating mutual innovation knowledge

Symbol systems can provide topic-specific languages comprising multimodal grammars and vocabularies. Symbol systems can facilitate mutual knowledge for innovation when people do not already have a common language for effective communication about an innovation. For example, there can be a lack of common language among diverse participants at public co-creation workshops: especially when different participants have different perspectives about the same hyped innovation. In this paper, action research is reported, which involved the development of a multimodal symbol system for facilitating mutual innovation knowledge. Overall, this paper provides two principal contributions to the literature. First, criteria for topic-specific symbol systems are set-out with reference to relevant literature. Second, a practical example of a multimodal symbol system, which meets these criteria, is presented. Together, these contributions introduce new directions for research and practice concerned with facilitating mutual innovation knowledge

Multilayer Traffic Engineering in Interworking Multihop wireless networks

The advancement in wireless networking and wireless device technology are paving the way for bringing the vision of ubiquitous communication to reality. This vision will be enabled by the interworking of existing wireless multihop wireless networks. However, the diversity in the design and operation of these wireless networks may not enable users to enjoy continuous network service as they traverse between networks. This paper presents a framework which ensures continuous service and sustains an acceptable service level quality for network users transiting between multiple multihop wireless networks. The focus is on the scenario where a user utilizes multiple hops to access any of the multiple networks. We classify the components of the framework into link discovery, resource optimization and routingprocesses. A set of analytical models and metrics are defined for these processes and the framework evaluated with simulations. The findings show that despite an increase in simultaneous network users, which degrades network performance, the framework is able to support quality continuous service for users transiting between networks

Кооперативна ретрансляція на основі протоколу простого адаптивного декодування та передачі

Мета роботи: розгляд та розробка адаптивного протоколу декодування та передачі. Розглядаються варіанти побудови простого та складного протоколу передачі, які дозволяють мінімізувати отримання помилкових повідомлень. В ході виконання даної роботи розглянуто засади кооперативної ретрансляції та адаптивного протоколу декодування та передачі, розроблено модель мережі з кооперативною ретрансляцією на основі простого адаптивного протоколу декодування та передачі, проведено моделювання та виконано аналіз результатів.Goal: consideration and development of an adaptive decode-and-forward protocol. Options for constructing a simple and complex decode-and-forward protocol are considered, which allow to minimize getting messages with errors. In the course of this work the principles of cooperative retransmission and adaptive decode-and-forward protocol are considered, a network model with cooperative retransmission based on a simple adaptive decoding and transmission protocol is developed, modeling is performed and the results are analyzed

Mathematical optimisation and signal processing techniques in wireless relay networks

With the growth of wireless networks such as sensor networks and mesh networks, the challenges of sustaining higher data rates and coverage, coupled with requirement for high quality of services, need to be addressed. The use of spatial diversity proves to be an attractive option due to its ability to significantly enhance network performance without additional bandwidth or transmission power. This thesis proposes the use of cooperative wireless relays to improvise spatial diversity in wireless sensor networks and wireless mesh networks. Cooperation in this context implies that the signals are exchanged between relays for optimal performance. The network gains realised using the proposed cooperative relays for signal forwarding are significantly large, advocating the utilisation of cooperation amongst relays. The work begins with proposing a minimum mean square error (MMSE) based relaying strategy that provides improvement in bit error rate. A simplified algorithm has been developed to calculate the roots of a polynomial equation. Following this work, a novel signal forwarding technique based on convex optimisation techniques is proposed which attains specific quality of services for end users with minimal transmission power at the relays. Quantisation of signals passed between relays has been considered in the optimisation framework. Finally, a reduced complexity scheme together with a more realistic algorithm incorporating per relay node power constraints is proposed. This optimisation framework is extended to a cognitive radio environment where relays in a secondary network forward signals without causing harmful interferences to primary network users.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Методи підвищення пропускної здатності мережі п’ятого покоління

Метою дослідження є детальний розгляд технології SFN, розробка алгоритму хендовера для підвищення швидкості передачі даних, огляд технології кооперативної ретрансляції. Для досягнення поставленої мети були сформульовані такі завдання: 1. Провести огляд технології SFN на прикладі мереж 5G; 2. Провести огляд сценаріїв міграції мережі LTE до 5G NR; 3. Навести схему алгоритму хендоверу Macro Cell – mmWave CellThe aim of the study is to take a detailed look at SFN technology, develop a handover algorithm to improve data transfer rates, and review cooperative retransmission technology. To achieve this goal, the following tasks were formulated: 1. Review SFN technology using 5G networks as an example; 2. review LTE network migration scenarios to 5G NR; 3. Give a diagram of the Macro Cell – mmWave Cell handover algorith

Conceção e desempenho de retransmissões sem fios cooperativas

Doutoramento em Engenharia Eletrotécnica/TelecomunicaçõesIn recent years, a new paradigm for communication called cooperative communications has been proposed for which initial information theoretic studies have shown the potential for improvements in capacity over traditional multi-hop wireless networks. Extensive research has been done to mitigate the impact of fading in wireless networks, being mostly focused on Multiple-Input Multiple-Output (MIMO) systems. Recently, cooperative relaying techniques have been investigated to increase the performance of wireless systems by using diversity created by different single antenna devices, aiming to reach the same level of performance of MIMO systems with low cost devices. Cooperative communication is a promising method to achieve high spectrum efficiency and improve transmission capacity for wireless networks. Cooperative communications is the general idea of pooling the resources of distributed nodes to improve the overall performance of a wireless network. In cooperative networks the nodes cooperate to help each other. A cooperative node offering help is acting like a middle man or proxy and can convey messages from source to destination. Cooperative communication involves exploiting the broadcast nature of the wireless medium to form virtual antenna arrays out of independent singleantenna network nodes for transmission. This research aims at contributing to the field of cooperative wireless networks. The focus of this research is on the relay-based Medium Access Control (MAC) protocol. Specifically, I provide a framework for cooperative relaying called RelaySpot which comprises on opportunistic relay selection, cooperative relay scheduling and relay switching. RelaySpot-based solutions are expected to minimize signaling exchange, remove estimation of channel conditions, and improve the utilization of spatial diversity, minimizing outage and increasing reliability.Nos últimos anos foi proposto um novo paradigma de comunicação, chamado de comunicação cooperativa, para o qual estudos iniciais de teoria da informação demonstraram ter potencial para melhorias na capacidade em redes sem fios tradicionais multi-hop. Uma extensa pesquisa tem sido realizada para mitigar o impacto da atenuação em redes sem fios, tendo-se debruçado principalmente em sistemas Multiple-Input Multiple-Output (MIMO). Recentemente têm sido investigadas técnicas de retransmissão cooperativas para aumentar o desempenho de sistemas sem fios, usando a diversidade criada por diferentes antenas individuais com o objetivo de atingir o mesmo nível de desempenho dos sistemas MIMO com dispositivos de baixo custo. A comunicação cooperativa é um método promissor para atingir uma elevada eficiência na ocupação espectral e melhorar a capacidade de transmissão em redes sem fios. A comunicação cooperativa tem por ideia base a junção de recursos de nós distribuídos para melhorar o desempenho global de uma rede sem fios. Em redes cooperativas os nós cooperam para ajudarem-se mutuamente. Um nó cooperativo que ofereça ajuda estará agindo como um intermediário ou mediador, podendo transmitir mensagens da origem para o destino. A comunicação cooperativa explora a natureza da transmissão em difusão das comunicações sem fios para formar antenas múltiplas virtuais com vários nós de rede independentes e com antenas únicas. Esta investigação visou contribuir para a área científica das redes sem fios cooperativas. O foco da pesquisa foi nos protocolos de controlo de acesso ao meio (MAC) com retransmissão cooperativa. Especificamente, proponho uma arquitetura para enquadrar a retransmissão cooperativa, chamada RelaySpot (ponto de retransmissão), que explora a seleção oportunista de retransmissores, o escalonamento de retransmissores cooperativos e a comutação entre retransmissores. As comunicações baseadas na RelaySpot deverão ter uma troca de sinalização reduzida, não usam estimativas das condições do canal e melhoram o aproveitamento da diversidade espacial, minimizando a interrupção e aumentando a fiabilidade