Implementation of Ad-Hoc Protocol On Tandem Multihop Wireless Network

The utilization of Internet of Things (IoT) technology, especially in remote areas, is still relatively low, even though the technology is required to implement smart farming or smart villages, which aims to improve the quality of life of people in rural areas. The high investment cost for IoT networks that still use cellular networks or Wi-Fi is one of the causes of the slow implementation of this technology. Our previous research has developed an alternative network for IoT devices in remote areas with the concept of a Tandem Multihop Wireless Network focusing on developing simple message scheduling. This research focuses on implementing ad-hoc routing protocols in tandem with multi-hop wireless to analyze the advantages and disadvantages of the protocol. Each sensor periodically sends data to the monitoring server via IoT devices on each tower. The scenario was implemented using MININET-WIFI. Evaluations were carried out to determine delivery probability, latency average, and jitter. In general, the two Ad-Hoc protocols tested, namely OLSR and BATMAN, had the same performance when the data sent was 1 MB, but when the data size was increased to 2 MB, the OLSR routing protocol on several nodes had better performance than BATMAN.The utilization of Internet of Things (IoT) technology, especially in remote areas, is still relatively low, even though the technology is required to implement smart farming or smart villages, which aims to improve the quality of life of people in rural areas. The high investment cost for IoT networks that still use cellular networks or Wi-Fi is one of the causes of the slow implementation of this technology. Our previous research has developed an alternative network for IoT devices in remote areas with the concept of a Tandem Multihop Wireless Network focusing on developing simple message scheduling. This research focuses on implementing ad-hoc routing protocols in tandem with multi-hop wireless to analyze the advantages and disadvantages of the protocol. Each sensor periodically sends data to the monitoring server via IoT devices on each tower. The scenario was implemented using MININET-WIFI. Evaluations were carried out to determine delivery probability, latency average, and jitter. In general, the two Ad-Hoc protocols tested, namely OLSR and BATMAN, had the same performance when the data sent was 1 MB, but when the data size was increased to 2 MB, the OLSR routing protocol on several nodes had better performance than BATMAN

Implementasi Ad-Hoc Protocol Pada Tandem Multihop Wireless Network

Pemanfaatan teknologi Internet of Things (IoT) terutama di daerah terpencil masih tergolong rendah, padahal teknologi tersebut juga dibutuhkan untuk implementasi smart farming atau smart village yang bertujuan meningkatkan kualitas hidup masyarakat di pedesaan. Mahalnya biaya investasi untuk jaringan IoT yang masih menggunakan jaringan selular atau Wi-Fi menjadi salah satu penyebab implementasi teknologi ini tergolong lambat. Penelitian kami sebelumnya telah mengembangkan jaringan alternatif untuk perangkat IoT di daerah terpencil dengan konsep jaringan Tandem Multihop Wireless Network dengan focus pada pengembangan simple message scheduling. Penelitan ini focus pada implementasi routing protocol ad-hoc pada tandem multihop wireless untuk menganalisis bagaimana kekurangan dan kelebihan protocol tersebut. Scenario pengujian dengan menempatkan perangkat IoT atau sensor pada tower jaringan Saluran Udara Tegangan tinggi (SUTET). Setiap sensor secara periodic mengirimkan data ke monitoring server melalui perangkat IoT pada setiap tower. Skenario tersebut, kemudian diimpelementasikan menggunakan MININET-WIFI. Pengujian dilakukan untuk mengetahui delivery probability, Latency Average, dan Jitter. Secara umum kedua protocol Ad-Hoc yang diuji yakni OLSR dan BATMAN memiliki performance yang sama ketika ukuran data yang dikirim adalah sebesar 1 MB, tetapi Ketika ukuran data dinaikkan menjadi sebesar 2 MB, routing protocol OLSR pada beberapa node memiliki performance lebih baik dari BATMAN

On Coding for Reliable Communication over Packet Networks

We present a capacity-achieving coding scheme for unicast or multicast over lossy packet networks. In the scheme, intermediate nodes perform additional coding yet do not decode nor even wait for a block of packets before sending out coded packets. Rather, whenever they have a transmission opportunity, they send out coded packets formed from random linear combinations of previously received packets. All coding and decoding operations have polynomial complexity. We show that the scheme is capacity-achieving as long as packets received on a link arrive according to a process that has an average rate. Thus, packet losses on a link may exhibit correlation in time or with losses on other links. In the special case of Poisson traffic with i.i.d. losses, we give error exponents that quantify the rate of decay of the probability of error with coding delay. Our analysis of the scheme shows that it is not only capacity-achieving, but that the propagation of packets carrying "innovative" information follows the propagation of jobs through a queueing network, and therefore fluid flow models yield good approximations. We consider networks with both lossy point-to-point and broadcast links, allowing us to model both wireline and wireless packet networks.Comment: 33 pages, 6 figures; revised appendi

Scheduling for tandemly-connected sensor networks with heterogeneous link transmission rates

As a simplest sensor network topology, a tandemly-connected multi-hop wireless network model is studied, in which nodes are tandemly arranged and serially connected by unreliable lossy links. Each node generates a data packet in every one cycle period and forwards it bounded for either of two gateways at both ends of the network; the gateways can send the data to a server using a loss-free infrastructure. In such environments, packet losses often happen due to not only attenuation and fading but also interference among links, thus unscheduled packet forwarding schemes are inefficient and suffer from a low success ratio of packet delivery to the server. In our previous paper, we proposed a centralized scheduling to design a static time-slot allocation for redundant packet transmission based on the positions and packet loss rates of links to maintain a high success probability of delivering all sensor data. However, it only considered homogeneous links with the same transmission rate, and also it is not optimal in some topological conditions. Therefore, in this paper, we essentially enhanced it to adapt to heterogeneous links with different transmission rates and to topological conditions that are not covered by the previous scheme. Our scheme analytically derives an optimal static time-slot allocation and combines it with forward erasure correction (FEC) against packet losses based on inter-packet XOR coding. The results of synthetic simulation have shown the validity of the analytical optimization, the benefit of coding, and the issues hard to consider in analytical models as well.The 34th International Conference on Information Networking (ICOIN 2020), January 7-10, 2020, Barcelona, Spai

Message Transmission Scheduling for Multi-hop Wireless Sensor Network with T-Shaped Topology

In multihop wireless sensor networks, packets are periodically generated at each node in every cycle period time and forwarded along lossy wireless links between adjacent nodes toward one of the gateways through which the packets can reach a central data collection server. To cope with frequent packet losses, we consider a TDMA-based packet scheduling with redundant transmissions. In our previous work, we propose an optimal scheduling for the tandemly-arranged network topology with two gateways at the both edges of the network; which is not always realistic. Therefore, in this paper, we extend the research to the T-shaped network topology with three gateways. We derive a static time-slot allocation for T-shaped topology, which maximizes the theoretical probability that all packets are successfully delivered to the server with the basic redundant transmission scheme in a limited cycle period; and show its benefit through numerical results. This extension significantly increases the applicability of our optimal scheduling scheme.15th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCA-2020), October 28-30, Yonago, Tottori, Japan（オンライン開催に変更

Transmission scheduling for tandemly-connected sensor networks with heterogeneous packet generation rates

A tandemly-connected multi-hop wireless sensor network model is studied. Each node periodically generates packets in every cycle and relays the packets in a store-and-forward manner on a lossy wireless link between two adjacent nodes. To cope with a considerable number of packet losses, we previously proposed a packet transmission scheduling framework, in which each node transmits its possessing packets multiple times according to a static time-slot allocation to recover or avoid packet losses caused either by physical conditions on links or by interference of simultaneous transmissions among near-by nodes. However, we assumed that the packet generation rate is identical over all nodes, which is not always realistic. Therefore, in this paper, we enhance our work to the case of heterogeneous packet generation rates. We derive a static time-slot allocation maximizing the probability of delivering all packets within one cycle period. By using an advanced wireless network simulator, we show its effectiveness and issues to be solved.12th International Workshop on Information Network Design (WIND-2020), in conjunction with 12th International Conference on Intelligent Networking and Collaborative Systems (INCoS-2020), August 31st - September 2nd, 2020, University of Victoria, Canada（新型コロナ感染拡大に伴い、現地開催中止

Network coding meets multimedia: a review

While every network node only relays messages in a traditional communication system, the recent network coding (NC) paradigm proposes to implement simple in-network processing with packet combinations in the nodes. NC extends the concept of "encoding" a message beyond source coding (for compression) and channel coding (for protection against errors and losses). It has been shown to increase network throughput compared to traditional networks implementation, to reduce delay and to provide robustness to transmission errors and network dynamics. These features are so appealing for multimedia applications that they have spurred a large research effort towards the development of multimedia-specific NC techniques. This paper reviews the recent work in NC for multimedia applications and focuses on the techniques that fill the gap between NC theory and practical applications. It outlines the benefits of NC and presents the open challenges in this area. The paper initially focuses on multimedia-specific aspects of network coding, in particular delay, in-network error control, and mediaspecific error control. These aspects permit to handle varying network conditions as well as client heterogeneity, which are critical to the design and deployment of multimedia systems. After introducing these general concepts, the paper reviews in detail two applications that lend themselves naturally to NC via the cooperation and broadcast models, namely peer-to-peer multimedia streaming and wireless networkin

TDMA-based scheduling for multi-hop wireless sensor networks with 3-egress gateway linear topology

We have studied packet transmission scheduling on multi-hop wireless sensor networks with 3-egress gateway linear topology, called Y-shaped topology. In every one cycle period, each node generates and forwards data packets that are bounded for either of the gateways at edges. In this paper, we focus on centrally-managed Time Division Multiple Access (TDMA)-based slot allocations and design a packet transmission scheduling framework combining with the basic redundant transmission to reduce and recover packet losses. On each of three types of path models to cover all possible routing on Y-shaped topology, we efficiently derive a global static time-slot allocation. The derived time-slot allocation exactly maximizes the probability that all packets are successfully delivered to one of the gateways within one cycle period, which cannot be achieved by existing scheduling schemes

Markov Decision Processes with Applications in Wireless Sensor Networks: A Survey

Wireless sensor networks (WSNs) consist of autonomous and resource-limited devices. The devices cooperate to monitor one or more physical phenomena within an area of interest. WSNs operate as stochastic systems because of randomness in the monitored environments. For long service time and low maintenance cost, WSNs require adaptive and robust methods to address data exchange, topology formulation, resource and power optimization, sensing coverage and object detection, and security challenges. In these problems, sensor nodes are to make optimized decisions from a set of accessible strategies to achieve design goals. This survey reviews numerous applications of the Markov decision process (MDP) framework, a powerful decision-making tool to develop adaptive algorithms and protocols for WSNs. Furthermore, various solution methods are discussed and compared to serve as a guide for using MDPs in WSNs

Optimal transfer schedule in a tandemly-connected sensor network with heterogeneous transmission rates

線的な領域を監視するセンサネットワークとして，センサと接続した中継ノードを直列に配置し，中継ノード間の簡易な無線通信を用いて，その両端にあるゲートウェイの片方までセンサデータを運ぶマルチホップ無線ネットワークを考える．ただしゲートウェイからサーバまでは信頼性のある通信インフラが使える．このような環境では，各無線リンクでの減衰やフェージング，リンク間干渉によりパケット損失が多発し，各ノードが無秩序にパケットを中継転送しても非効率でサーバへのパケット到達率は低い．先行研究では，ノードの位置やリンクの損失率を考慮し，ACKを使わない計画冗長転送によってパケット損失に対処する場合のパケット到達率を最大化するスロット割り当てと，FECを使う転送パケット選択とを組み合わせる手法を提案したが，リンクの伝送速度が均一の場合のみを扱った．そこで本研究では，リンクの伝送速度が不均一な場合にも拡張したパケット転送スケジュールを提案する．これにより，伝送速度が異なるリンクだけでなく，物理伝送速度が同じでも干渉によって実効伝送速度が異なるリンクも扱える．その有効性や課題を，現実に近い無線環境シミュレーションによって分析・評価した． / As a sensor network to monitor a large elongated area, a multi-hop wireless network model is considered in which relay nodes accommodating sensors are arranged in tandem and connected by simple wireless links, and deliver the sensor data to gateways at both ends of the line. The gateways can reliably send the data to a server using an infrastructure. In such environments, since packet losses often happen due to an attenuation/fading on each link and an interference among links, an unscheduled packet forwarding is inefficient and the success ratio of packet delivery to the server is low. In our previous report, we proposed a packet transfer scheduling consisting of a slot allocation based on node positions and link loss rates, which maximizes the success delivery ratio of all sensor data when using planned retransmissions without ACK against packet losses, and a forwarding packet selection based on FEC, but it is only for homogeneous links with the same transmission rate. Therefore, in this report, we propose an enhance version of the packet transfer scheduling to adapt to heterogeneous links not only with different physical transmission rates but with variable effective transmission rates depending on interferences. Simulations reflecting realistic wireless communications were conducted for evaluation, and have shown the usefulness of our proposal and some issues to be solved as well.電子情報通信学会 情報通信マネジメント研究会（ICM）, 2018年7月5日-6日, 青森市, 日