INTERFACE MODE ASSIGNMENT METHOD FOR SELF-RECONSTRUCTION OF WIRELESS MESH NETWORKS

The key features of computer networks available for disaster situation is reliable, fault tolerance and self-configurable. Therefore, using wireless mesh network for disaster prevention and recover system has gain much attention from the research community in last decades. In addition, from the practical aspects of the network infrastructures of the disaster system, we should assume the core capabilities such as wireless connectivity in wide range, ease of use, and low cost so on. In this paper, we propose an interface mode assignment method for reconstructing a route from an isolated router to a gateway (GW) router in a wireless mesh network based on IEEE 802.11 infrastructure mode after a disaster occurrance. The proposed method assigns an adequate mode to each interface in an isolated router to recover the network reachability in distributed manner. Simulation results show the effectiveness of the proposed method via two different scenarios

Improving the Performance of MANET Gateway Selection Scheme for Disaster Recovery

In this paper, we propose an improved MANET gateway selection scheme suitable for disaster recovery applications. Having an infrastructure less and decentralize features, MANET is well suited to bring the network back that has been collapse after a disaster. We focus on improving throughput performance of MANET by designing a better gateway selection scheme. The key idea is to eliminate the congestion at each MANET gateway for improved performance. Simulation results show that the proposed gateway selection scheme can efficiently manage the traffic distribution at each gateway to maximize the network performance

Distributed Time Division Multiple Access (DTDMA) Medium Access Control Protocol For Wireless Sensor Networks [TK7872.D48 W872 2008 f rb].

Rangkaian sensor tanpa wayar menerima perhatian yang memberangsangkan sejak beberapa tahun yang lalu disebabkan oleh peningkatan permintaan terhadap perisian kadar rendah, murah dan menjimatkan tenaga seperti operasi perkilangan, ketenteraan, kesihatan, pengawasan alam sekitar, sekuriti, operasi penyelamatan dan komunikasi tanpa wayar. Wireless Sensor Networks (WSNs) received tremendous attention over the last few years due to increasing demand for low data rate, low-cost and low power applications in industries like factory automation, military, health and hospitality,environment monitoring, security, search and rescue, and wireless communications

Device-to-device based path selection for post disaster communication using hybrid intelligence

Public safety network communication methods are concurrence with emerging networks to provide enhanced strategies and services for catastrophe management. If the cellular network is damaged after a calamity, a new-generation network like the internet of things (IoT) is ready to assure network access. In this paper, we suggested a framework of hybrid intelligence to find and re-connect the isolated nodes to the functional area to save life. We look at a situation in which the devices in the hazard region can constantly monitor the radio environment to self-detect the occurrence of a disaster, switch to the device-to-device (D2D) communication mode, and establish a vital connection. The oscillating spider monkey optimization (OSMO) approach forms clusters of the devices in the disaster area to improve network efficiency. The devices in the secluded area use the cluster heads as relay nodes to the operational site. An oscillating particle swarm optimization (OPSO) with a priority-based path encoding technique is used for path discovery. The suggested approach improves the energy efficiency of the network by selecting a routing path based on the remaining energy of the device, channel quality, and hop count, thus increasing network stability and packet delivery

Network virtualization in next-generation cellular networks: a spectrum pooling approach

The hardship of expanding the cellular network market results from the tremendous high cost of mobile infrastructure, i.e. the capital expenditures (CAPEX) and the operational expenditures (OPEX). Spectrum Sharing is one of the proposed solution for the high-cost of scalability of cellular networks. However, most of the proposed spectrum pooling frameworks in the literature are mostly approached from a technical view besides there are no good cost models based on real datasets for quantifying the circumstances under which sharing the spectrum and network resources would be beneficial to mobile operators. In this thesis, by studying different sharing scenarios in a fiber-based backhaul mobile network, we assess the incentives for service providers (SPs) to share spectrum/infrastructure in different cellular market areas/economic areas (CMA/BEAs) with different population density, allocated bandwidth (BW), spectrum bid values and considering different network topologies. Moreover, we look at the technical problem of sharing the spectrum between two SPs sharing the same basestation (BS), yet they have different traffic demand as well as different QoS constraints. We design a resource allocation scheme to provision real-time (RT), non-real-time (NRT) as well as Ultra-reliable Low Latency Communications (URLLC) traffic in a single shared BS scenario such that SPs achieve isolation, fairness and enforce their QoS constraints. Finally, we exploit spectrum pooling to develop an approach for dynamically re-configuring the base stations that survive a disaster and are powered by a microgrid to form a multi-hop mesh network in order to provide local cellular service

Models and Protocols for Resource Optimization in Wireless Mesh Networks

Wireless mesh networks are built on a mix of fixed and mobile nodes interconnected via wireless links to form a multihop ad hoc network. An emerging application area for wireless mesh networks is their evolution into a converged infrastructure used to share and extend, to mobile users, the wireless Internet connectivity of sparsely deployed fixed lines with heterogeneous capacity, ranging from ISP-owned broadband links to subscriber owned low-speed connections. In this thesis we address different key research issues for this networking scenario. First, we propose an analytical predictive tool, developing a queuing network model capable of predicting the network capacity and we use it in a load aware routing protocol in order to provide, to the end users, a quality of service based on the throughput. We then extend the queuing network model and introduce a multi-class queuing network model to predict analytically the average end-to-end packet delay of the traffic flows among the mobile end users and the Internet. The analytical models are validated against simulation. Second, we propose an address auto-configuration solution to extend the coverage of a wireless mesh network by interconnecting it to a mobile ad hoc network in a transparent way for the infrastructure network (i.e., the legacy Internet interconnected to the wireless mesh network). Third, we implement two real testbed prototypes of the proposed solutions as a proof-of-concept, both for the load aware routing protocol and the auto-configuration protocol. Finally we discuss the issues related to the adoption of ad hoc networking technologies to address the fragility of our communication infrastructure and to build the next generation of dependable, secure and rapidly deployable communications infrastructures

이기종 IoT 기기간 협력을 통한 네트워크 성능 향상

학위논문(박사) -- 서울대학교대학원 : 공과대학 전기·정보공학부, 2022. 8. 박세웅.The Internet of Things (IoT) has become a daily life by pioneering applications in various fields. In this dissertation, we consider increasing transmission data rate with energy efficiency, extending transmission coverage with low power, and improving reliability in congested frequency bands as three challenges to expanding IoT applications. We address two issues to overcome these challenges. First, we design a layered network system with a new structure that combines Bluetooth Low Energy (BLE) and Wi-Fi networks in a multi-hop network. Based on the system, we propose methods to increase data rate with energy efficiency and extend transmission coverage in a low-power situation. We implement the proposed system in the Linux kernel and evaluate the performance through an indoor testbed. As a result, we confirmed that the proposed system supports high data traffic and reduces average power consumption in the testbed compared to the existing single BLE/Wi-Fi ad-hoc network in a multi-hop situation. Second, we tackle the adaptive frequency hopping (AFH) problem of BLE through cross-technology communication (CTC) and channel weighting. We design the AFH scheme that weights the channels used by BLE devices with improving reliability in the congested bands of both Wi-Fi and BLE devices. We evaluate the proposed scheme through prototype experiments and simulations, confirming that the proposed scheme increases the packet reception rate of BLE in the congested ISM band compared to the existing AFH algorithm.사물인터넷은 현재 다양한 영역에서 application을 개척하여 생활화되어 왔다. 이 학위 논문에서는 사물인터넷의 응용 사례 확장을 위해 에너지 효율적인 전송 속도 향상, 저전력 상황에서의 전송 범위 확장, 혼잡한 대역에서의 신뢰성 향상을 새로운 도전 과제로 삼고, 이러한 도전 과제를 극복할 두 가지 주제를 다룬다. 첫째, 다중 홉 네트워크 상황에서의 블루투스 저전력과 Wi-Fi 네트워크를 결합 한 새로운 구조의 계층적 네트워크 시스템을 설계하고 이에 기반한 에너지 효율적인 전송 속도 향상 및 저전력 상황에서의 전송 범위확장을 제안한다. 제안된 시스템은 Linux 커널에 구현하여 실내 테스트베드를 통해 성능을 평가한다. 결과적으로 제안 한 기법이 다중 홉 상황에서 기존 블루투스 저전력/Wi-Fi 단일 ad-hoc 네트워크와 비교하여 높은 데이터 트래픽을 지원하며, 테스트베드에서의 평균 전력 소비를 줄 이는 것을 확인한다. 둘째, Cross-technology Communication (CTC)과 채널 가중치를 통한 블루투스 저전력의 Adaptive Frequency Hopping (AFH) 문제를 해결한다. 최종적으로 블루투스 저전력 기기가 사용하는 채널에 가중치를 두는 AFH 기법을 설계하여 Wi-Fi 와 블루투스 저전력 기기가 모두 혼잡한 대역에서의 신뢰성을 향상한다. 프로토타입 실험과 시뮬레이션을 통해 제안한 기법이 기존의 AFH 기법과 비교하여 혼잡한 ISM 대역에서 블루투스 저전력의 패킷 수신율을 증가시키는 것을 확인한다.1 Introduction 1 1.1 Motivation 1 1.2 Contributions and Outline 2 2 Wi-BLE: On Cooperative Operation of Wi-Fi and Bluetooth Low Energy under IPv6 4 2.1 Introduction 4 2.2 Related Work 7 2.2.1 Multihop Connectivity for Wi-Fi or BLE 7 2.2.2 Multi-radio Operation 11 2.3 System Overview 13 2.3.1 Control Plane 13 2.3.2 Data Plane 16 2.3.3 Overall Procedure 16 2.4 MABLE: AODV Routing over BLE 17 2.4.1 BLE Channel Utilization 17 2.4.2 Joint Establishment of Route and Connection 20 2.4.3 Link Quality Metric for BLE Data Channels 22 2.4.4 Bi-directional Route Error Propagation 25 2.5 Wi-BLE: Wi-Fi Ad-hoc over BLE 27 2.5.1 Radio Selection 27 2.5.2 Routing and Radio Wake-up for Wi-Fi 30 2.6 Evaluation 32 2.6.1 BLE Routing 33 2.6.2 Wi-Fi Routing over BLE 35 2.6.3 Radio Selection 38 2.7 Summary 40 3 WBC-AFH: Direct Wi-Fi to BLE Communication based AFH 41 3.1 Introduction 41 3.2 Background 45 3.2.1 Frequency hopping in BLE 45 3.2.2 Cross Technology Communication 47 3.3 Proposed AFH 49 3.3.1 CTC based informing 50 3.3.2 Weighted channel select 51 3.3.3 Hopping set size optimization 52 3.3.4 WBC-AFH 54 3.4 Evaluation 57 3.4.1 Setup 57 3.4.2 Robustness 60 3.4.3 Reliability 61 3.5 Future Work 65 3.6 Summary 66 4 Conclusion 67박

Multihop relay techniques for communication range extension in near-field magnetic induction communication systems

In this paper, multihop relaying in RF-based com munications and near field magnetic induction communication (NFMIC) is discussed. Three multihop relay strategies for NFMIC are proposed: Non Line of Sight Magnetic Induction Relay (NLoS-MI Relay), Non Line of Sight Master/Assistant Magnetic Induction Relay1 (NLoS-MAMI Relay1) and Non Line of Sight Master/Assistant Magnetic Induction Relay2 (NLoSMAMI Relay2). In the first approach only one node contributes to the communication, while in the other two techniques (which are based on a master-assistant strategy), two relaying nodes are employed. This paper shows that these three techniques can be used to overcome the problem of dead spots within a body area network and extend the communication range without increasing the transmission power and the antenna size or decreasing receiver sensitivity. The impact of the separation distance between the nodes on the achievable RSS and channel data rate is evaluated for the three techniques. It is demonstrated that the technique which is most effective depends on the specific network topology. Optimum selection of nodes as relay master and assistant based on the location of the nodes is discussed. The paper also studies the impact of the quality factor on achievable data rate. It is shown that to obtain the highest data rate, the optimum quality factor needs to be determined for each proposed cooperative communication method. © 2013 ACADEMY PUBLISHER