30 公立はこだて未来大学理事

31 IEEE Japan Council Vice Chair

32 Editor, Journal of Ambient Intelligence & Humanized Computing

33 平成25年度宮城県高度情報化推進協議会副会長

田中 良明　教授TANAKA, Yoshiaki　Professor

論文誌

1 B. Yang, R. Yamamoto, and Y. Tanaka, “Dempster-Shafer Evidence Theory Based Trust Management Strategy against Cooperative Black Hole Attacks and Gray Hole Attacks in MANETs”, ICACT Transactions on the Advanced Communications Technology, Vol. 2, No.3, pp. 223-232, May 2013.

【要約】The MANETs have been experiencing exponential growth in the past decade. However, their vulnerability to various attacks makes the security problem extremely prominent. The main reasons are its distributed, self-organized and infrastructure independent natures. As concerning these problems, trust management scheme is a common way to detect and isolate the compromised nodes when a cryptography mechanism shows a failure facing inner attacks. Among huge numbers of attacks, black hole attack may col-lapse the network by depriving the route of the normal communication. The conventional proposed method achieved good perfor-mance facing black hole attack, while failing to detect gray hole attacks. In this paper, a Dempster-Shafer （D-S） evidence based trust management strategy is proposed to conquer not only cooperative black hole attack but also gray hole attack. In the proposed method, a neighbour observing model based on watchdog mechanism is used to detect single black hole attack by focusing on the direct trust value （DTV）. Historical evidence is also taken into consideration to go against gray hole attacks. Then, a neighbour recommendation model companied with indirect trust value （ITV） is used to figure out the cooperative black hole attack. D-S evidence theory is implemented to combine ITVs from different neighbours. Some of the neighbour nodes may declare a false ITV, which effect can also be diminished through the proposed method. The simulation is firstly conducted in the Matlab to evaluate the performance of the algorithm. Then the security routing protocol is implemented in the GloMoSim to evaluate the effectiveness of the strategy. Both of them show good results and demonstrate the advantages of proposed method by punishing malicious actions to prevent the camouflage and deception in the attacks.

2 山本 嶺, 三好 匠, 田中 良明, “アドホックネットワークにおける送信速度制御を用いた近傍トラヒック適応形負荷分散手法”，電子情報通信学会論文誌（B）, Vol. J96-B, No. 7, pp. 782-792, 2013年７月.

【要約】アドホックネットワークでは，移動する端末同士が自律分散的にネットワークを構築して通信を行うため，ネットワーク内の通信状態を一元的に管理することが困難である．そのため，端末密度が高く，通信環境が安定している箇所や端末ほどトラヒックが集中しやすく，ネットワーク内における通信の公平性を低下させる要因となりうる．この問題に対し，経路制御によって負荷分散を実現する手法やTCP制御の効率化によって通信効率を向上させる手法が提案されている．しかし，経路探索に基づく手法では，端末の移動に伴う最適通信経路の変化や負荷の大きな変動に対応することが困難である．また，アドホックネットワーク向けのTCPでは，通信効率の向上を主な目的としているため，ネットワーク全体として適切な制御とならない可能性がある．本論文では，漏れ聞きを利用して把握した近傍端末の通信状態とHelloメッセージの交換によって取得した情報に基づいて送信速度制御を行うことで負荷分散を実現する手法を提案している．また，コンピュータシミュレーションを用いた性能評価を行い，提案手法が高い負荷分散効果を示し，効率的な通信を実現できることを示している．

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3 X. Wang, F. Balasis, S. Xu, and Y. Tanaka, “Sparse Placement of Wavelength Convertible 3R Regenerators and Joint Resource Assignment in

Large-Scale Optical Networks”, IEICE Transactions on Communications, Vol. E96-B, No. 7, pp. 1845-1856, July 2013.

【要約】It is believed that the wavelength switched optical network （WSON） technology is moving towards being adopted by large-scale networks. Wavelength conversion and signal regeneration through reamplifying, reshaping, and retiming （3R） are beneficial to support the expansion of WSON. In many cases, these two functions can be technically integrated into a single shared physical component, namely the wavelength convertible 3R regenerator （WC3R）. However, fully deploying such devices is infeasible due to their excessive cost. Thus, this topic serves as a motivation behind the investigation of the sparse placement issue of WC3Rs presented in this paper. A series of strategies are proposed based on knowledge of the network. Moreover, a novel adaptive routing and joint resource assignment algorithm is presented to provision the lightpaths in WSON with sparsely placed WC3Rs. Exten-sive simulation trials are conducted under even and uneven distribution of WC3R resource. Each strategic feature is examined for its efficiency in lowering the blocking probability. The results reveal that carefully designed sparse placement of WC3Rs can achieve performance comparable to that of full WC3R placement scenario. Furthermore, the expenditure of WC3R deployment also depends on the type of used WC3Rs characterized by the wavelength convertibility, i.e., fixed WC3R or tunable WC3R. This paper also investigates WSON from the perspective of cost and benefit by employing different types of WC3Rs in order to find the possibility of more efficient WC3R investment.

4 B. Gu, K. Yamori, S. Xu, and Y. Tanaka, “Multi-Stage Non-cooperative Game for Pricing and Connection Admission Control in Wireless

Local Area Networks”,IEICE Transactions on Communications, Vol. E96-B, No. 7, pp. 1986-1996, July 2013.

【要約】This paper focuses on learning the economic behaviour of the access point （AP） and users in wireless local area networks （WLANs）, and using a game theoretic approach to analyze the interactions among them. Recent studies have shown that the AP would adopt a simple, yet optimal, fixed rate pricing strategy when the AP has an unlimited uplink bandwidth to the Internet and the channel capacity of WLAN is unlimited. However, the fixed rate strategy fails to be optimal if a more realistic model with limited capacity is considered. A substitute pricing scheme for access service provisioning is hence proposed. In particular, the AP first estimates the probable utility degradation of existing users consequent upon the admission of an incoming user. Second, the AP decides: （i） whether the incoming user should be accepted; and （ii） the price to be announced in order to try to maximize the overall revenue. The condition, under which the proposed scheme results in a perfect Bayesian equilibrium （PBE）, is investigated.

5 F. Balasis, X. Wang, S. Xu, and Y. Tanaka, “Dynamic Physical Impairment-Aware Routing and Wavelength Assignment in 10/40/100 Gbps

Mixed Line Rate Optical Networks”, ICACT Transactions on Advanced Communications Technology （TACT）, Vol. 2, No. 6, pp. 343-351, November 2013.

【要約】The growing global Internet traffic will inevitably lead to a serious upgrade of the current optical networks’ capacity. Instead of upgrading the data rate of each wavelength in every fibre link across the entire optical WDM network infrastructure, it is more efficient and cost-effective to support different data rates within one fibre link （e.g., 10, 40 and 100 Gbps）. This is called optical network with mixed line rates （MLR）. Moving to higher than 10Gbps data rates that can be used within the same fibre requires the implementation of phase modulation schemes. Nevertheless, the co-existing OOK channels cause a critical physical impair-ment to the phase modulated channels, namely cross-phase modulation （XPM）, that limits the network’s performance. In order to mitigate this type of impairment a more sophisticated physical impairment aware routing and wavelength assignment scheme needs to be adopted. In this paper, the critical impairment for each data rate and the way it affects quality of transmission （QoT） is presented. Secondly, QoT aware RWA schemes for a MLR optical network are presented and evaluated in terms of performance through simulations.

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6 C. Zhang, B. Gu, K. Yamori, S. Xu, and Y. Tanaka, “Duopoly Competition in Time-Dependent Pricing for Improving Revenue of Network Service

Providers”, IEICE Transactions on Communications, Vol. E96-B, No. 12, pp. 2964-2975, December 2013.

【要約】Due to network users’ different time-preference, network traffic load usually significantly differs at different time. In traffic peak time, network congestion may happen, which make the quality of service for network users deteriorate. There are essentially two ways to improve the quality of services in this case: （ 1） Network service providers （NSPs） over-provision network capacity by investment; （2） NSPs use time-dependent pricing （TDP） to reduce the traffic at traffic peak time. However, over-provisioning network capacity can be costly. Therefore, some researchers have proposed TDP to control congestion as well as improve the revenue of NSP. But to the best of our knowledge, all of the literature related time-dependent pricing scheme only consider the monopoly NSP case. In this paper, a duopoly NSP case is studied. The NSPs try to maximize their overall revenue by setting time-dependent price, while users choose NSP by considering their own preference, congestion status in the networks and the price set by the NSPs. Analytical and experimental results show that the TDP benefits the NSPs, but the revenue improvement is limited due to the competition effect.

国際学会

7 B. Yu, B. Gu, K. Yamori, and Y. Tanaka, “Modelling of Access Point Selection Based on Wireless QoS Demand”, 28th International Technical Conference on Circuits/Systems, Computers and Communications （ITC-CSCC 2013）, Yeosu, Korea, July 2013.

【要約】The popularity of wireless network is increasing. Most public areas such as train stations, shopping malls, parks, airports are covered by access points （APs）. Unfortunately, traffic load is often distributed unevenly among these public APs, leading to an inefficient utilization of bandwidth resources. Furthermore, the wireless networks allow a more flexible communication model since users are not limited to a fixed location. An effective way to alleviate the load-imbalance problem is to guide those users, who feel frustrated with the current transmission rate, to move from a heavily-loaded AP with lower transmission rate to a lightly loaded AP with higher transmission rate. In this paper, we propose an AP selection model to investigate the probabilities of users’ movement deci-sion given the transmission rate of the current AP and that of the recommended AP and the decision tree. We also build a user movement decision tree to predict the users’ movement decision based on the results of a questionnaire survey.

8 B. Gu, C. Zhang, K. Yamori, and Y. Tanaka, “A Greedy Algorithm for Connection Admission Control in Wireless Random Access Networks”, 19th Asia-Pacific Conference on Communications （APCC 2013）, Bali Island, Indonesia, Session 1, 2 pages, August 2013.

【要約】In this paper, we consider a price-based connection admission control （CAC） for wireless random access networks. In particular, a network operator determines sequential prices to dynamically maintain the traffic admitted into the network below the channel capacity. The CAC tries to ensure quality of service （QoS） guarantees to users and hence maximize the overall revenue. We find that the revenue maximization problem over all sequential prices is NP-hard. Therefore, a greedy algorithm is employed for obtain-ing a simple, easy-to-implement solution.

9 B. Gu, C. Zhang, K. Yamori, and Y. Tanaka, “Distributed Connection Admission Control Integrated with Pricing for QoS Provisioning and Revenue Maximization in Wireless Random Access Networks”, 15th Asia-Pacific Network Operations and Management Symposium （APNOMS 2013）, Hiroshima, Japan, Paper No. TS3-1, 5 pages, September 2013.

【要約】This paper studies the impact of connection admission control （CAC） on the congestion management practices and the revenue of a monopoly access point （AP）. The AP provides congestion-indication signals that suggest users to choose their access probabili-ties in response to network loading conditions. A Stackelberg leader-follower game is then formulated to analyze the interaction

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between the AP and the users. In particular, the AP first estimates the probable utility degradation of existing users consequent upon the admission of an incoming user. Second, the AP decides whether the connection of the incoming user should be admitted or not. The proposed CAC policy is completely distributed and can be implemented by individual APs using only local informa-tion. Simulation results show that the proposed algorithm achieves higher saturation throughput as well as greater revenue gain when compared with an existing algorithm.

10 C. Zhang, B. Gu, S. Xu, K. Yamori, and Y. Tanaka, “Time-Dependent Pricing for Revenue Maximization of Network Service Providers Considering

Users Preference”, 15th Asia-Pacific Network Operations and Management Symposium （APNOMS 2013）, Hiroshima, Japan, Paper No. TS3-3, 6 pages, September 2013.

【要約】Due to network users’ different time-preference, network traffic load differs significantly at different time. In traffic-peak time, the quality of service provided to network users may deteriorate due to congestion. There are two ways to improve the quality of services: （1） Network service providers （NSPs） over-provision network capacity by investment; （2） NSPs use pricing to reduce the traffic at traffic-peak time by exploiting the elasticity of demand with respect to price. However, over-provisioning network capacity can be costly. Therefore, some researchers have proposed time-dependent pricing to control congestion as well as improve the revenue of NSP. To the best of our knowledge, all of the literature related to time-dependent pricing scheme only considers the monopoly NSP case. In this paper, a duopoly NSP case is studied. The NSPs try to maximize their overall revenue by setting time-dependent price, while users choose NSP by considering their own preference, congestion status in the networks, the price set by the NSPs and the switching cost set by NSPs. Analytical and experimental results show that the time-dependent pricing （TDP） benefits the NSPs, but the revenue improvement is limited due to the competition effect.

11 X. Fan, B. Yang, R. Yamamoto, and Y. Tanaka,“Road Side Unit Assisted Stochastic Multi-hop Broadcast Scheme for Instant Emergency Message

Propagation”, 16th International Conference on Advanced Communication Technology （ICACT2014）, Phoenix Park, Korea, Session 1F-01, pp. 103-108, February 2014.

【要約】VANET （Vehicular ad hoc Network） is a special kind of ad hoc wireless network where every single node is a vehicle moving in a relatively high velocity, which leads to exclusive challenges like rapid changing topologies, safety and privacy concerns. In this specific network, the propagation of emergency messages could be critical to save human lives and property. Many researchers have proposed routing or broadcast protocols to solve the problems in VANET. The objective of this paper is to propose a broad-cast scheme in VANET that is not likely to cause broadcast storm problem with a reasonable delay and high delivery rate. Since VANET is an attack-prone network and any kind of malicious behaviour in VANET might cause serious loss or even death in reality, we should also refrain from using beacons to exchange privacy-sensitive information in V2V （Vehicle to Vehicle）. In this paper, a multi-hop broadcast scheme that makes use of RSU and V2I （Vehicle to Infrastructure） communication is proposed. The simulation result shows that the proposed scheme outperforms static stochastic broadcast scheme in terms of delivery rate. Com-paring to flooding, we offer a better delay and less network usage.

12 Z. Huang, R. Yamamoto, and Y. Tanaka, “A Multipath Energy-Efficient Probability Routing Protocol in Ad Hoc Networks”, 16th International Conference on Advanced Communication Technology （ICACT2014）, Phoenix Park, Korea, Session 1F-03, pp. 244-250, February 2014.

【要約】Ad hoc networks are decentralized type of wireless networks. Moreover, ad hoc networks are characterized by random, multi-hop topologies that may change rapidly over time because of mobile nodes. However, since nodes in ad hoc networks operate on limited battery energy and it is impractical to recharge or replace the battery, an energy-efficient protocol is important in the design of ad hoc networks. By conventional routing protocols, a shortest path is always selected in ad hoc networks. Without considering the energy consumption, some nodes will exhaust very soon and ad hoc networks will become partitioned. Improving routing protocols to prolong the lifetime of ad hoc networks has been a hot research area in the past few years. However, most of protocols only focus on the constrained battery energy. In this paper, a new protocol is proposed. It is a multipath energy-efficient probability routing

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protocol based on AODV （MEP-AODV）. In MEP-AODV, not only battery energy consumption but also multipath selection is considered. By the proposed protocol, when an intermediate node received a request packet （RREQ）, it won’t relay the RREQ immediately. It will relay the RREQ with a probability which is based on its remaining battery energy. After the RREQ arrived at the destination node, it won’t trigger a reply packet （RREP） at once until the expiry of a delay timer. The destination will select multiple paths with sufficient battery energy from the collected paths after the timer expired. Then the destination node initiates the corresponding RREPs. The source node can send data packets via the selected multiple paths by a probability function which is based on the minimum node remaining battery energy of one path. This proposed protocol is implemented in QualNet to evaluate the performance. From the results, MEP-AODV shows the good energy efficiency in terms of the maximizing the lifetime of ad hoc networks.

13 P. Baklan, K. Yamori, and Y. Tanaka, “Measure of User Behaviour before and during Disaster Congestion”, 16th International Conference on Advanced Communication Technology （ICACT2014）, Phoenix Park, Korea, Session 2A-01, pp. 135-140, February 2014.

【要約】Network congestion during large scale disasters seems inevitable. Sudden influx of traffic caused by users calling their loved ones, coupled with the possibility that many base stations and routers in the area are damaged by the disaster; leads to resource shortage which causes congestion, which in turn causes many users becoming disgruntled and their quality of experience dropping. If a study can be made on predicting user behaviour, based on usual user habits and way of acting immediately after a disaster, then the network provider can regulate traffic accordingly or take precautions in areas within disaster zones.

研究会

14 神谷 優, 矢守 恭子, 田中 良明, “ジャンル学習に基づくSNS画像推薦の実装と評価”，電子情報通信学会技術研究報告, Paper No. CQ2013-28, Vol. 113, No. 208, pp. 1-4, 2013年９月.

【要約】ソーシャルネットワークサービス（SNS）における画像推薦では協調フィルタリングが用いられることが多く，コンピュータ資源や時間を多く要する．そのため，多くのSNSでは，推薦指標はオフラインで算出し，その結果をオンラインに反映させる方法をとっている．本稿では，画像のジャンル情報を用いてリアルタイムに画像推薦を行うWebアプリケーションを実装し，推薦の効果を評価している．

15 白井 達也, 山本 嶺, 三好 匠, 田中 良明, “アドホックマルチキャストにおける局所回復経路制御手法”（奨励講演）, 電子情報通信学会技術研究報告, Paper No. NS2013-160, Vol. 113, No. 360, pp. 149-154, 2013年12月.

【要約】一般に，同一情報を複数ノードに配信するサービスでは，マルチキャスト通信が有効であり，アドホックネットワークでは，無線通信の同報性を利用することで一度の送信で複数のノードにデータを配信することが可能である．しかし，従来のマルチキャストルーチングプロトコルでは，ノード移動によってトポロジーが変化した場合，経路再構築が必要となり，配信遅延の増加やパケット配信率の低下などの問題が生じる．本稿では，アドホックネットワークでより効率的なマルチキャスト通信を実現するため，ODMRP （On-demand multicast routing protocol）を基に，GPSなどから得られる位置情報及び経路障害検知を用いたマルチキャストルーチングプロトコルを提案している．提案手法では，局所的なリンク切断を早期に回復し，配信元からの経路再構築を抑制することで，効率的なマルチキャスト通信を実現している．また，シミュレーション評価により提案方式の優位性を示している．

16 B. Yang, R. Yamamoto, and Y. Tanaka, “A Principal-Agent Theory based Game Theoretic Incentive Method for Packet Forwarding in Ad

Hoc Networks”,IEICE Technical Report on Communication Quality, Paper No. CQ2013-69, Vol. 113, No. 405, pp. 11-16, January 2014.

【要約】Dropping packets is one of the most devastating threatens on a performance of ad hoc networks. Among various motivations of

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dropping packets, selfishness and malicious attack are the main two factors. However, there are still some other cases of dropping packets caused by networking context such as mobility, congestion, and traffic load. Incentive mechanism is a typical method to induce node to participate in relaying packets for other adjacent nodes. However, most of them neglect a noise of dropping packets by networking context or just omit this important factor for brevity. In this paper, a principal-agent theory based game theoretic incentive method is proposed for encouraging each node contributing into packet forwarding, which will result in a high perfor-mance cooperative network. Holmstrom-Milgrom model, which is a simplified principal-agent model with a linear reward scheme, is implemented to model the relationship between two adjacent nodes. In each two pair-wise nodes model, the node requests for relaying packets is seen as a principal node while the node forwarding packets is denoted as an agent node. A credit given by prin-cipal node to agent node as incentive compensation is the contract, which is designed by principal node based on agent node’s effort in forwarding packets. Dropping packets by networking is also taken into consideration as an exogenous uncertainty. It is proven that there is an optimal incentive strategy can encourage packet forwarding even under noise effect. Numerical evaluations are also conducted to evaluate the performance of the proposed method.

17 B. Yu, B. Gu, K. Yamori, and Y. Tanaka, “A Multiobjective Approach for Improving Association Control in Wireless LANs”,

IEICE Technical Report on Communication Quality, Paper No. CQ2013-106, Vol. 113, No. 471, pp. 101-106, March 2014.

【要約】Fairness and network utility are both important indicators to measure the performance of wireless local area networks （WLANs）. However, it is challenging to obtain a desirable association control configuration to achieve good fairness and high aggregate throughput, where multiple indicators are used simultaneously as optimization goals. It is even more challenging if some of these indicators are conflict with each other, where an increment of an indicator deteriorates another. In this paper, we propose a genetic algorithm based multiobjective optimization approach to conduct user-AP association control to find Pareto optimal solution set for both fairness and the aggregate throughput. The method also consider the minimum quality of service （QoS） for each user. Furthermore, we perform experiments to evaluate the fairness and aggregate throughput, and compare the method with existing received signal strength indication （RSSI） method to demonstrate the efficiency of the method.

大会

18 山本 嶺, 山崎 託, 三好 匠, 田中 良明, “アドホックネットワークにおける端末移動に基づくOpportunistic Routing”, 2013年電子情報通信学会通信ソサイエティ大会, 通信講演論文集２, No. B-6-66, p. 66, 2013年９月.

【要約】アドホックネットワークでは，AODVなどの特定の経路を利用してパケット転送を行うルーチングプロトコルが一般的に用いられている．一方，通信環境が随時変動するアドホックネットワークで効率的なパケット通信を実現するため，パケット転送時に通信環境が優れているリンクを確率的に選択するOpportunistic routing （OR）が提案されている．ORでは，通信成功率，ホップ数，距離などの指標に基づいて転送端末を選択し，各リンクでの通信を最適化することで，エンドエンド間の通信効率向上を実現している．本稿では，移動性の高い環境において，高効率，高信頼なORを実現する手法を提案している．

19 神谷 優, 矢守 恭子, 田中 良明, “ジャンル学習に基づくSNS画像推薦手法の評価”, 2013年電子情報通信学会通信ソサイエティ大会, 通信講演論文集２, No. B-11-17, p. 331, 2013年９月.

【要約】ソーシャルネットワークサービス（SNS）における画像推薦手法に関しては，協調フィルタリングなどが用いられている．協調フィルタリングは，計算量が多く，コンピュータ資源や時間を多く要する．そのため，多くのSNSでは，推薦指標はオフラインで算出し，その結果をオンラインに反映させる方法をとる．本稿では，画像のジャンル情報を用いることにより，リアルタイムに画像推薦を行うことができるWebアプリケーションを実装し，被験者に実験してもらうことで評価している．

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20 X. Fan, B. Yang, R. Yamamoto, and Y. Tanaka, “Direction-Based Relay Selection Scheme for Alert Message Broadcast in VANET”, 2013 IEICE Communications Society Conference, No. BS-7-9, pp. S-49-S-50, September 2013.

【要約】With the rapid growth of automotive usage, vehicles suffer from road accident, sudden change of the road condition, fog bank, and even robbery. One of the major solutions to mitigate the loss caused by accident is inter vehicle communication （IVC）, a major research topic in ad hoc networks explicitly used for vehicular ad hoc networks （VANET）. Major services provided by VANETs are traffic telematics and emergency notification that could mitigate the damage to a certain degree. Since nodes in VANET move at a high velocity, achieving a required delay and a dissemination range becomes difficult. In order to overcome the difficulties that existed in VANET, many IVC broadcast protocol was proposed based on IEEE 802.11 broadcast scheme such as PRP. This paper proposes a scheme to proactively determine which vehicle will make use of the notification by checking the direction and distance from a source node and prioritize it to be a relay node for further rebroadcast. As a basic assumption, every vehicle was equipped with GPS to determine its own location and is able to determine its direction and velocity. The proposed scheme could be used in almost any conventional broadcast protocol and it also has compatibility to original IEEE 802.11 broadcast scheme.

21 Z. Huang, R. Yamamoto, and Y. Tanaka, “A Power-Aware Routing Protocol in Ad Hoc Networks”, 2013 IEICE Communications Society Conference, No. BS-7-12, pp. S-55-S-56, September 2013.

【要約】Ad hoc networks can be deployed without any pre-existing infrastructures. Thus, they are easy to be established and there is a broad range of applications in ad hoc networks. However, energy consumption issue gradually becomes an important topic in ad hoc networks since ad hoc networks are energy constrained. As concerns this, a lot of researches go to the direction that is how to conserve energy and prolong the lifetime of ad hoc networks. A power-aware routing algorithm becomes crucial in the design of ad hoc routing protocols. In this paper, SR-AODV （Power-aware protocol based on PAR-AODV with selective routing） is proposed. In SR-AODV, routes are selected based on different energy levels of nodes.

22 B. Yang, X. Fan, R. Yamamoto, and Y. Tanaka, “Simulation Analysis of Flooding-Based DDoS Attack in Ad Hoc Networks”, 2013 IEICE Communications Society Conference, No. BS-7-14, pp. S-59-S-60, September 2013.

【要約】Distributed denial of service （DDoS） attack is a devastating threat not only in traditional wired networks but also in wireless net-works such as ad hoc networks and wireless sensor networks （WSN）. It is well known that DDoS is lunched by a large amount of zombies which are sporadically located in the network and can make a machine resource unavailable to its intended users. Ad hoc network is especially vulnerable to DDoS for the weakness of it: once a node is compromised, it can do malicious actions at will and from inside. In this paper, simulation of flooding based DDoS attack is done to analyse the difference of it in ad hoc environment. It is apparently that not only a target server node but also nodes on a route will be affected by the attack. Simulation is conducted to study the relationship between the node’s density around a server node and the performance of the attack.

23 B. Yu, B. Gu, K. Yamori, and Y. Tanaka, “Modelling of User’s Movement Decision Based on QoS Demand in Wireless Networks”, 2013 IEICE Communications Society Conference, No. BS-7-20, pp. S-71-S-72, September 2013.

【要約】The popularity of wireless network is growing explosively during recent years. Most public areas, such as train stations, shopping malls, and airports, are covered with free or un-free access points （APs）. In these areas the traffic load is often distributed unevenly among these public APs. Otherwise, the users are not limited to a fixed location or network any more, since the wireless networks allow a more flexible communication model. The user’s mobility can easily influence network traffic load. An effective way is to recommend an AP with a higher transmission rate for a user who feels frustrated with his/her current transmission rate. The user’s movement decision in wireless network often follows several specific patterns. To modelling these patterns of user’s movement decision and recommend a location with suitable transmission rate accurately are beneficial for both the network resource manage-ment and quality of service （QoS） guarantees for users. Our previous work made a questionnaire to survey the user’s behaviour under different network conditions. By using the information, such as transmission rate of current and recommended AP, user’s age, sex, and occupation, it is possible to build a decision tree and to predict the user’s movement decision. In this paper, we build

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a decision tree to predict the user’s movement decision by considering the network environment and user’s diversity. The decision tree can accurately classify the users into two different movement decision classes.

24 B. Gu, K. Yamori, and Y. Tanaka, “Game Modelling of Connection Admission Control for Random Access Networks”, 2013 IEICE Communications Society Conference, No. BS-7-22, pp. S-75-S-76, September 2013.

【要約】We consider connection admission control （CAC） for random access networks that support the CSMA family of protocols. Such protocols provide zero-coordination by allowing users to contend for channel access arbitrarily. When two or more users transmit a packet simultaneously, the packets collide and are dropped; such packets must be transmitted again at a later time. A key feature of such random access networks is that the network can become unstable if the traffic admitted into the network exceeds the channel capacity. Therefore, CAC policy is essential for ensuring a stable operation of the network. In this paper, a Stackelberg leader-follower game is structured to analyze the interactions between an AP and each incoming user. Specifically, an incoming user chooses an access probability so as to optimize his/her payoff （i.e., the best response strategy）. Given the best response strategy, the AP can derive the private information, such as the priority of each user’s willingness to pay, through backward induction. The AP then estimates whether the revenue growth from the incoming user is able to compensate for the revenue loss incurred by the quitting of existing users, and decides whether the connection of the incoming user should be admitted or not. The proposed CAC policy is completely distributed and can be implemented by individual APs using only local information.

25 Sheng Xu, F. Balasis, X. Wang, Sugang Xu, and Y. Tanaka, “A Dynamic Allocation Algorithm for Achieving the Fair Uplink Bandwidth and Effective Distri-

bution in Fibre-Wireless Networks”, 2013 IEICE Communications Society Conference, No. BS-7-30, pp. S-91-S-92, September 2013.

【要約】This paper studies a dynamic bandwidth allocation in FiWi access network which consists of passive optical network （PON） and wireless access network parts. The mobile users attach to the closed access point （AP）, and ONU which the AP is connected. In such an environment, with the movement of users, the traffic distributed in FiWi networks will be changed from time to time, e.g., causing the shift of congestion point in FiWi. Therefore, it is expected that the bandwidth allocation can be rearranged accordingly to mitigate the congestion. An algorithm is proposed for bandwidth allocation. It takes account of ONU bandwidth request and a pre-configured threshold value on bandwidth allocation.

26 X. Wang, F. Balasis, S. Xu, and Y. Tanaka, “Dynamic Grooming Routing and Resource Assignment in Translucent 10/40/100Gbps Mixed

Line Rate WDM Networks”, 2013 IEICE Communications Society Conference, No. BS-7-33, pp. S-97-S-98, September 2013.

【要約】Wavelength division multiplexing （WDM） technology has been widely employed to provide high-bandwidth networks. Cur-rently, the 10Gbps/40Gbps WDM systems have been commercially deployed by network operators. In near future, 100Gbps line-rate will also appear in the WDM network. The coexistence of different line-rates results in a mixed-line-rate （MLR） WDM network , which introduces more flexibility to the heterogeneous traffic requirements in realistic networks. However, due to the accumulated physical impairment （PI）, different line-rate wavelengths have different optical reaches. Beyond this reach, 3R regen-eration （reamplifying, reshaping, and retiming） is required to continuously transmit optical signals healthily. In current stage, the solution of sparse placement of optoelectronic 3R regenerators in the network has been widely recognized in academy and industry. To further improve the bandwidth utilization, a number of low granularity requests can also be grouped into a large bandwidth lightpath, termed as grooming. In this paper, we mainly study the grooming, routing, and resource assignment （GRRA） problem and propose a dynamic GRRA algorithm for MLR network in high efficiency of bandwidth utilization.

27 F. Balasis, X. Wang, S. Xu, and Y. Tanaka, “Traffic Grooming in Wavelength Switched Optical Networks with Mixed Line Rates”, 2013 IEICE Communications Society Conference, No. BS-7-34, pp. S-99-S-100, September 2013.

【要約】There is no doubt that the increasingly heterogeneous Internet traffic demands a more versatile architecture to utilize the network

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resources in a more optimal way. Traffic grooming and mixed line rate （MLR） optical networks are two different approaches that try to resolve the issue of inefficient bandwidth usage. Although there is growing number of research works that are focusing either on traffic grooming or mixed line rates in optical networks, very few works concern an optical network that combines these two elements. In this paper, a heuristic method of traffic grooming in a MLR optical network will be shown and a cost comparison will be made between an optical network with one data rate, and a MLR optical network with grooming capabilities.

28 C. Zhang, B. Gu, K. Yamori, S. Xu, and Y. Tanaka, “Price Competition between Content Provider and Internet Service Provider”, 2013 IEICE Communications Society Conference, No. BS-7-42, pp. S-113-S-114, September 2013.

【要約】The network technology or capacity to provide better quality of service （QoS） for end users. However, new broadband applica-tions generate huge amount of traffic, which originates from the existence of content providers （CPs）, without generating direct revenues for ISPs. Hence, ISPs want to get additional revenues from CPs that are not directly connected to them. One choice for ISPs is to charge the CPs. Actually, whether ISPs can charge CPs or not remains the center of network neutrality* debate. In Japan, the Ministry of Internal Affairs and Communictions （MIC） has published a series of white papers related to network neutrality debate. According to MIC, the pricing between ISPs and CPs can be left to consultation among ISPs and CPs. In this paper, non-network neutrality is assumed: the ISP can charge CP to cover the investment cost. A simplified market, which is composed of one ISP, one CP, and large number of users is considered in this paper. The ISP charges end users based on their usage. The CP charges end users the subscription fee. Furthermore, the ISP also charges the CP to cover the investment cost. A novel Stackelberg-Ber-trand game is proposed to obtain the equilibrium price of ISP and CP. At the first stage of the Stackelberg-Bertrand game, the ISP sets the price for CP. Then in the second stage of the game, the ISP and the CP play a Bertrand game. We solved the equilibrium of the Stackelberg-Bertrand game by backward induction. Given the price set for CP by ISP, the Bertrand game between the ISP and CP is solved firstly. Then the ISP sets the optimal price to charge CP through backward induction. The main contribution of this paper are as following: A novel Stackelberg-Bertrand game is proposed to model the noncooperative behaviour between the ISP and the CP; The effect of payment from CP to ISP is evaluated.

29 P. Baklan, K. Yamori, and Y. Tanaka, “A New Quality of Experience Service Model during Disasters”, 2013 IEICE Communications Society Conference, No. BS-7-49, pp. S-126-S-127, September 2013.

【要約】Quality of Experience （QoE） is an emerging aspect of modern telecommunications. It combines technological specifications of a network with basic human psychology, economics and social sciences. While techno-centric quality assessments like Quality of Service （QoS） are mainstream and widely used, it is the mindset and general feeling of content that a customer experiences that define the satisfaction and their willingness to pay for the network. During disaster scenarios where the system is crippled due to both results of structural damage and increased traffic due to the affected calling their loved ones; telephone networks are inevitably congested. User’s QoE is defined mainly by his/her interests, age, social background etc,. While during a disaster, the user’s QoE would drastically change. Rerouting traffic during catastrophic failure is already studied by Li et al. and a framework is proposed, general user behaviour is not included in the QoS sense in their study. Although we can assume the traffic load will increase proportionally with the scale of the disaster, it should also be taken into account that internet traffic will also fluctuate, especially social media flooding with users trying to get firsthand information about the disaster or simply the affected posting that they are unharmed. It can be considered that in an M/M/c service model, a possible catastrophe can downsize service trunks c while exponentially increasing load.

30 佐藤 拓朗, 朴 容震, 津田 俊隆, 後藤 滋樹, 田中 良明, 亀山 渉, 嶋本 薫, 甲藤 二郎, 市野 将嗣, “交通機関を利用したコンテンツ配信システム”，2014年電子情報通信学会総合大会, 通信講演論文集２, No. B-6-88, p. 88, 2014年３月.

31 矢守 恭子, 田中 良明, “交通機関を利用した先回りコンテンツ配信のQoE”, 2014年電子情報通信学会総合大会, 通信講演論文集２, No. B-6-95, p. 95, 2014年３月.

【要約】筆者らは，モバイルトラヒックの爆発的な増加に対応するために，モビリティを活用した効率的な先回りコンテンツ

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配信方式について検討している．本稿では，経済学的アプローチを用い，通信サービスに対するユーザ体感品質QoE を下げることなく効率的にコンテンツを配信するスケジュール手法について検討している．

32 山本 嶺, 山崎 託, 三好 匠, 田中 良明, “アドホックネットワークにおける転送履歴に基づくOpportunistic Routing”, 2014年電子情報通信学会総合大会, 通信講演論文集２, No. B-6-159, p. 159, 2014年３月.

【要約】一般に，アドホックネットワークでは，ネットワークトポロジーの変化や端末の参加及び離脱が頻繁に発生し，安定した通信環境を構築することが困難である．そこで，パケット転送時に通信環境が優れているリンクや中継端末を確率的に選択するOpportunistic routing （OR）が提案されている．ORでは，ホップ数や通信成功率などの指標に基づいて，日和見的に中継端末を選択することで，エンド間の通信成功率向上や通信遅延の低減を実現している．本稿では，中継端末の転送履歴に基づき，安定した中継端末選択を行うORを提案し，通信遅延の低減，通信効率の向上を実現している．

33 須藤 晃史, 矢守 恭子, 田中 良明, “アクセスポイント選択問題解決のためのユーザ誘導手法”, 2014年電子情報通信学会総合大会, 通信講演論文集２, No. B-11-17, p. 465, 2014年３月.

【要約】ユーザは無線LANサービスを利用する際，複数のアクセスポイント（AP）から接続するAPを選択する．このとき，ユーザの分布によって，APごとにユーザの接続数に偏りが生じ，ユーザは無線資源を効率的に利用することができない．この問題はAP選択問題と呼ばれる．本稿では，ユーザの偏りを解決する手段として，ユーザの移動（モビリティ）に着目し，ユーザに情報を与えることで，空いているAPに誘導する制御法を提案する．アンケートの結果，約５割のユーザが誘導に従うことが分かった．

34 岡本 司, 三宅 功, 矢守 恭子, 田中 良明, “企業ユーザ向け帯域確保サービスにおけるQoS選択の効果”, 2014年電子情報通信学会総合大会, 通信講演論文集２, No. B-11-24, p. 472, 2014年３月.

【要約】本検討では，これまで，ユーザが通信要求の際に，追加料金を払って帯域確保での通信を実行するか否かをその都度判断し，確保される帯域が料金に見合わないと判断した場合には，リンクの空き帯域を利用した無料のベストエフォートでの通信が可能であるサービスを想定していた．本稿では，このように状況に応じてQoSを選択できることがユーザ便益や事業者収入に与える影響を評価している．

35 T. Dai, R. Yamamoto, and Y. Tanaka, “Parameter Selection Method for Accurate Available Bandwidth Estimation by pathChirp”, 2014 IEICE General Conference, No. BS-1-13, pp. S-25-S-26, March 2014.

【要約】Characterizing an end-to-end network available band-width is of great importance for various network applications. However, due to the scale of Internet, traffic volume and probing algorithm make it a very challenging task to measure the available bandwidth accurate-ly. The probing method improved in this paper is one of the probing gap method based on the concept of “self-induced congestion” called pathChirp. The accuracy of pathChirp is depends on excursions it detects. However, parameters of a pathChirp will affect the excursion detection result. As concerned of this, this paper proposes a new method to select parameters in order to get a better perfor-mance of available bandwidth estimation. Moreover, traffic load is concerned as an aspect of parameter selection in this new method.

36 T. Shirai, R. Yamamoto, T. Miyoshi, and Y. Tanaka, “A Reliable Routing Method Using Local Repair for Ad Hoc Multicasting”, 2014 IEICE General Conference, No. BS-1-22, pp. S-42-S-43, March 2014.

【要約】Generally, multicast communications are well suited for data distribution services in ad hoc networks due to its wireless broadcast nature. Unstable wireless communications, however, cause considerable deterioration of packet delivery rate and delayed deliv-ery in conventional multicast routing protocols. This paper proposed a novel multicast routing protocol with alternative route

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construction considering nodes’ mobility prediction and link failure notification based on local repair mechanism in order to ef-ficiently enhance the transmission reliability in wireless ad hoc multicast networks.

37 Z. Huang, R. Yamamoto, and Y. Tanaka, “A Novel Min-Max Residual Battery-Aware Routing Protocol for Ad Hoc Networks”, 2014 IEICE General Conference, No. BS-1-23, pp. S-44-S-45, March 2014.

【要約】Ad hoc networks are decentralized wireless network which can be deployed without any fixed infrastructures, such as routers in wired networks. All the nodes in ad hoc networks can act as routers or terminals to participate in transmitting data packets. Thus, ad hoc networks are easy to be established. In ad hoc networks, all the nodes operate on batteries. If some nodes are used often, they will exhaust their battery energy faster than others. This will result in the partition of the ad hoc network. Therefore, energy-aware issue gradually becomes an important topic in ad hoc networks. However, conventional routing protocols do not consider energy consumption. As concerns this problem, developing an energy-aware routing protocol in ad hoc networks has been a hot research area in the past years. How to conserve energy and prolong the lifetime of ad hoc networks are crucial in the design of energy-aware routing protocols. In this paper, a new min-max residual battery routing protocol （MAODV） which is based on MMBCR （Min-Max Battery-aware Cost Routing） is proposed. In MAODV, routes are selected based on different energy levels of nodes.

38 B. Yang, R. Yamamoto, and Y. Tanaka, “A Novel Packet Forwarding Incentive Strategy based on Principal-Agent Theory in Ad Hoc Networks”, 2014 IEICE General Conference, No. BS-1-24, pp. S-46-S-47, March 2014.

【要約】There are good reasons that nodes in ad hoc networks should be encouraged to cooperate with each other for forwarding packets, for instance, ad hoc networks lack the networking infrastructure and each node can be selfish or malicious and so on. Thus, incen-tive methods for collaboration in packet forwarding are taken into consideration in some researches. However, these researches mainly focus on dropping packets aroused by nodes’ selfish or malicious behaviour rather than that associated with the networking context such as mobility, congestion, traffic load, etc. In this paper, a novel packet forwarding incentive strategy is proposed based on principal-agent theory. The virtual monetary, with the name of credit, is exploited to compensate the node relaying packets by the one calling for forwarding service. The node sending packets acts as a principal, while the node relying packets is seen as an agent. The aggregate packets dropped for the sake of networking environment are considered as exogenous risk. This paper explores to explain how to design the principal-agent model as an incentive strategy in Ad hoc networks and tries to find the equilibrium condition for the game under predefined assumptions.

39 D. Zhang, Sheng Xu, F. Balasis, Sugang Xu, and Y. Tanaka, “Two RWA Schemes Minimizing XPM in 10/40/100Gbps Mixed-Line-Rate WDM Optical Networks”, 2014 IEICE General Conference, No. BS-1-27, pp. S-52-S-53, March 2014.

【要約】The benefit of mixed line rate （MLR） networks is a cost-effective way to carry heterogeneous traffic. A shared sub-connection protection scheme was proposed to protect the MLR networks. And, the author studied the cost-efficiency of this proposal through an ILP model. However, the cross-phase modulation impairment （XPM） that is induced to 40Gbps and 100Gbps xPSK channels by adjacent 10Gbps on-off keying （OOK） channels is not taken into account. In this paper, in order to satisfy the users’ lightpath requests （with both the working and protection lightpaths）, and minimize the utilization of the network resources at the same time, two integer linear programming （ILP） models for the routing and wavelength assignment （RWA） problem are proposed. For the mitigation of XPM impairment, in Model-A the wavelength allocation are conducted in three isolated sections of wavelength spectrum according to the desired data rates, i.e., 10Gbps, 40Gbps and 100Gbps. Meanwhile, in Model-B, different from the specification of wavelength usage introduced in Model-A, new constraints are introduced so as to avoid the adjacent allocation of wavelengths for lightpaths with OOK and xPSK modulation formats. In both of these two models, for each request the working and protection lightpaths are to be established on two link-disjointed routes. If any of these two lightpaths cannot be established, the request is blocked.

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40 Sheng Xu, D. Zhang, F. Balasis, Sugang Xu, and Y. Tanaka, “A Model of Resource Allocation in RoF-WDM-PON Systems for Flexible Resource Utilization”, 2014 IEICE General Conference, No. BS-1-28, pp. S-54-S-55, March 2014.

【要約】When large aggregation of the mobile users occurs nearby the optical network unit （ONU） in radio-over-fibre wavelength divi-sion multiplexing passive optical network （RoF-WDM-PON）, the capacity of system needs to be increased to accommodate the increasing number of users. On the contrary, when the density of wireless users in the area of an ONU decreases, it is expected that the unused resource can be retrieved and employed for other places. Namely, the fluctuation of users’ demands leads to a big gap in the resource consumption. Instead of dimensioning the whole RoF-WDM-PON system to support the peak-value demands for all the areas, a flexible resource allocation is highly desired to utilize the system resource in a cost-efficient way. Based on this concern, in this paper, a model of resource allocation in RoF-WDM-PON is introduced firstly. The target herein is to enable the flexible resource arrangement, e.g., for resource addition and recall. It should be noted that although a fixed number of resources at ONU site are fixedly equipped, where the transmitters at optical line terminal （OLT） side and wavelengths in WDM-PON systems can be rearranged and reused by different ONUs according to the changes in wireless users’ distribution. For simplicity, this paper is focused on the modelling of downlink resource allocation.

41 F. Balasis, D. Zhang, Sheng Xu, Sugang Xu, and Y. Tanaka, “Minimizing the Cost of OFDM-Based Elastic Optical Networks”, 2014 IEICE General Conference, No. BS-1-29, pp. S-56-S-57, March 2014.

【要約】Elastic optical networks that make use of orthogonal frequency division multiplexing （OFDM） is one of the most promising technologies to deal with the explosive growth and highly heterogeneous nature of global Internet traffic. The greatest benefits of an elastic optical network are its high spectrum efficiency and unprecedented flexibility in bandwidth allocation. In this paper, an integer linear programming （ILP） formulation is presented with the objective of minimizing the cost of such network.

42 B. Yu, B. Gu, K. Yamori, and Y. Tanaka, “A Multiobjective Approach for Improving Association Control in Wireless LANs”, 2014 IEICE General Conference, No. BS-1-31, pp. S-60-S-61, March 2014.

【要約】Fairness and aggregate throughput are both important indicators to measure the performance of wireless local area networks （WLANs）. However, it is challenging to obtain a desirable association control configuration to achieve good fairness and high aggregate throughput, where multiple indicators are used simultaneously as optimization goals. It is even more challenging if some of these indicators are conflict with each other, where an increment of an indicator deteriorate another. In this paper, we propose a genetic algorithm based multiobjective optimization approach to conduct user-AP association control to find Pareto optimal solutions for both fairness and aggregate throughput. Our method also guarantees the minimum quality of service （QoS） for each user. Furthermore, we perform simulations to evaluate the fairness and aggregate throughput, and compare with our method with existing techniques like received signal strength indication （RSSI） to demonstrate the effectiveness of our technique.

43 P. Baklan, K. Yamori, and Y. Tanaka, “Prediction Mapping of Post-Disaster User Behaviour”, 2014 IEICE General Conference, No. BS-1-50, pp. S-94-S-95, March 2014.

【要約】

Post-disaster congestion remains a problem both on the network provider and on the users. After a big disaster, the network in-frastructure such as base stations may be toppled, or network routes may be cut off. The remaining network resources will not be enough for the exponential increase in user traffic. If a disaster map can be made considering users’ predicted movement and their potential traffic during and after the disaster, it will be easier and more efficient for network planners to place the sectors accordingly. Therefore, we can take into account user’s behaviour prediction and the civic landscape pf the given location to achieve a better understanding of resource needs. Each sector of a cell will be directed towards the best possible alignment.

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44 B. Gu, C. Zhang, K. Yamori, and Y. Tanaka, “Integration of Discounting Service with Admission Control for Flattening out Peak-Time Usage”, 2014 IEICE General Conference, No. BS-1-62, pp. S-115-S-116, March 2014.

【要約】The fluctuation of bandwidth demand throughout the day has long been a problem for Internet Service Provider （ISP）. During traffic peak time, ISP faces significant pressure to provide users with enough bandwidth to satisfy their QoS requirements. During off-peak time, bandwidth resources are more than enough, resulting in a waste of network capacity. Since there are many users distributed in the network that compete for the limited bandwidth resources, and each of them has his/her own preference over ac-cess time, several issues must be dealt with: efficient bandwidth allocation to the different sources considering their different QoS requirements; the ability of flattening out peak demand; the ability to implement the bandwidth allocation in a distributed way with minimal communication overheads.

45 X. Li, B. Gu, K. Yamori, and Y. Tanaka, “Pricing and Revenue Management in Cloud Computing”, 2014 IEICE General Conference, No. BS-1-64, pp. S-119-S-120, March 2014.

【要約】In recent years, cloud computing has attracted much attention not only from industry but also from academia, and the use of cloud computing has increased rapidly in many organizations. Cloud computing is defined as a large scale distributed computing para-digm for cloud providers （CPs） to host and deliver computing resources to companies and tenants who use such services. The CPs such as Amazon Elastic Compute （EC2） and Google AppEngine, deliver cloud users （CUs） Infrastructure as a Service （IaaS） and Software as a Service （SaaS）, respectively, according to resource types. The study of using pricing schemes for resource alloca-tion in communication networks is not a new topic. Since the seminal work of Kelly, there have been numerous works adopting pricing schemes to do studies on resource allocation problems in wireless communication networks. Generally speaking, there are two types of pricing schemes, that are flat-rate pricing and usage-based pricing. Some researchers studied local area networks with usage-based pricing. The shifting of pricing scheme from flat-rate pricing to usage-based pricing scheme is becoming popular in wireless communication networks. Some wireless network service providers such as China Mobile, China Unicom and AT&T have adopted usage-based pricing policy. The widespread use of cloud resources is making the efficient utilization and revenue manage-ment in cloud computing environments increasingly important. Some studies emerged about pricing in cloud computing recently, and a statistical model for the spot prices of EC2 was proposed. In this paper, we study the problem of revenue management problems for a monopolistic CP and multiple CUs operating on an IaaS cloud with fixed capacity. We not only study usage-based pricing where a CU’s total payment is linearly proportional to the allocated cloud resources, but also study the uniform pricing mechanism and pricing with guarantee. The objective of the CP is to maximize his net utility. The interaction between the CP and the CUs can be modelled as a Stackelberg game. We try to explore the effect of pricing on cloud resources and revenue management in an IaaS context. A microeconomic model is developed.

46 C. Zhang, B. Gu, K. Yamori, S. Xu, and Y. Tanaka, “Pricing Content Provider Considering Advertisers’ Participation”, 2014 IEICE General Conference, No. BS-1-66, pp. S-123-S-124, March 2014.

【要約】Internet service providers （ISPs） keep investing in the network technology or capacity to provide better quality of service （QoS） for end users. However, new broadband applications generate huge amount of traffic, which originates from the existence of content providers （CPs）, without generating direct revenues for ISPs. Hence, ISPs want to get additional revenues from CPs that are not directly connected to them. One choice for ISPs is to charge the CPs. In our previous work, non-network neutrality was assumed, and a simplified market, which is composed of one ISP, one CP, and large number of users was considered. The ISP charges end users based on their usage. The CP charges end users the subscription fee. Furthermore, the ISP also charges the CP to cover the investment cost. A novel Stackelberg-Bertrand game is proposed to study the noncooperative behaviour between ISP and CP, the Nash equilibrium of the Bertrand game between the ISP and CP has been established and impact of payment charged by ISP for CP has been evaluated. The numerical results show that the price elasticity of ISP and CP severely affects the payoff of the ISP and CP. The model in our previous work in which CP directly charges end users may be suitable for CP like IPTV providers. However, most of other CPs, like Youtube, provide contents for free, but collect revenues from online dvertisement. In this paper, it is considered that CP does not directly charge end users, but charges advertisers for getting revenue.

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47 Y. Chen, B. Gu, K. Yamori, and Y. Tanaka, “Time-Dependent Pricing for Realizing Maximum Revenue of VOD Type IPTV Service Provider”, 2014 IEICE General Conference, No. BS-1-70, pp. S-131-S-132, March 2014.

【要約】With the development of Internet technology, the users who access to broadband are increasing dramatically. At the same time, with the population of mobile devices, such as: smart phone and tablet computer, etc., people can use these mobile devices to enjoy IPTV services conveniently, wherever they are, and whenever they like. All this factors will lead IPTV services to an indispensable network entertainment service in the future. However, with more and more users use IPTV services, the traffic congestion problem comes out. Pricing of IPTV services has important influence on users’ behaviour. IPTV services are classified as follows: Video on Demand Service, Download Service, Live Television Service, and Time-Shifted Television Service. This paper proposes pricing scheme based on Video on Demand type IPTV service. In this paper, we adopt different prices in different time slot to control users’ demand during peak time and off-peak time. Hence, Quality of Service （QoS） can be maintained at a certain level, at the same time maximum revenue can be maximized for IPTV service provider.

48 X. Fan, B. Yang, R. Yamamoto, and Y. Tanaka, “Reliability Enhancement for Stochastic Broadcast in VANET”, 2014 IEICE General Conference, No. BS-1-74, pp. S-139-S-140, March 2014.

【要約】With the technology developing and motorization around the world, security of vehicles is becoming extremely important for protecting drivers and their property. As a part of intelligent transporting system （ITS）, inter-vehicle communication （IVC） pro-vides infrastructure independent communication method for propagating emergency messages between vehicles. One of the most critical techniques is vehicular ad hoc network （VANET）. However, its rapid changing network topology and drivers’ safety con-cerns make it a very challenging research area. In general, in order to propagating emergency message, the system uses a different broadcast schemes according to the different situation. The simplest broadcast scheme is pure flooding, which means every node relays the message it receives to maximize the delivery rate and dissemination range. However this will cause nodes to broadcast messages repeatedly that consumes network resources and lead to collisions, which is also called broadcast storm problem. In order to solve the problem, researchers have proposed many schemes which are generally categorized into 4 categories: location-based, counter-based, distance-based and probability-based broadcast. Practical schemes are often variation or hybrid of those schemes. Although many researchers focus on the broadcast scheme itself, there still remains a problem to be solved. That is, there is no efficient way to know if the message is successfully delivered or not. Some researchers are aware of this problem and they address the problem as “Reliability” and proposed several solutions to their own broadcast schemes. This paper focus on dealing with “Reliability” problem in a general way by proposing a generic reliability enhancement, which could be applied to all stochastic

broadcast schemes.

表彰

49 田中 良明 , 電子情報通信学会功績賞 , 2013年５月 .

50 白井 達也, 電子情報通信学会ネットワークシステム英語セッション奨励賞, “Alternate Route Construction Method Using Node Mobility Prediction for Ad Hoc Multicasting”, 2013年10月.

51 樊 星, （田中良明共著）, ICACT Outstanding Paper Award, “Road Side Unit Assisted Stochastic Multi-hop Broadcast Scheme for Instant Emergency Message

Propagation”，2014年２月.

52 山本 嶺, 電子情報通信学会ネットワークシステム研究賞, “アドホックネットワークにおける２ホップ信頼性制御を用いたブロック伝送方式”，2014年３月.

53 フィリポス・バラシス, （田中良明共著）, 電子情報通信学会学術奨励賞, “Offline Impairment-Aware RWA and Regenerator Placement in Optical Networks with Mixed Line

Rates”, “Traffic Grooming in Wavelength Switched Optical Networks with Mixed Line Rates”, 2014年３月.

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社会活動・学会活動

54 国立情報学研究所客員教授

55 日本 ITU協会出版・編集委員会委員長

56 日本クレジット協会インフラ整備部会副部会長

57 NTT R&Dアドバイザリーボードメンバー

58 日本技術者教育認定機構理事

59 電子情報通信学会理事

60 電子情報通信学会通信ソサイエティ会長

61 電子情報通信学会アクレディテーション委員会委員長

62 電子情報通信学会ネットワークシステム研究専門委員会顧問

63 電子情報通信学会テレコミュニケーションマネジメント研究専門委員会顧問

64 電子情報通信学会編集顧問

65 John Wiley & Sons International Journal of Network Management Editorial Advisory Board Member

66 Asia-Pacific Network Operations and Management Symposium Steering Committee Member

67 13th IFIP/IEEE Symposium on Integrated Network and Service Management （IM 2013） Technical Program Committee Member

68 14th IEEE/IFIP Network Operations and Management Symposium （NOMS 2014） Technical Program Committee Member

津田 俊隆　教授（任期付）TSUDA, Toshitaka　Professor

国内発表

1 XIONG Yu, Masako NAMEKI, Toshitaka TSUDA, “Rumor Propagation Analysis Based on Users’ State Model and Rumor Restraining Study”,

Kansai section Joint Convention of Institutes of Electrical Engineering, Nov. 2013.

2 XIONG Yu, Masako NAMEKI, Toshitaka TSUDA, “Analysis of Difference between Real Data and Simulation of Rumor Propagation Model”,

IEICE. General Conference, March 2014.

3 MorsalinUz Zoha and Toshitaka Tsuda,“ROI coding Approach -Towards Developing a Rate-Distortion Optimized Video Compression Algorithm for Remote Healthcare”, Kansai section Joint Convention of Institutes of Electrical Engineering, Nov. 2013.

4 佐藤 拓朗, 朴 容震, 津田 俊隆, 後藤 滋樹, 田中 良明, 亀山 渉, 嶋本 薫, 甲藤 二郎, 市野 将嗣, “交通機関を利用したコンテンツ配信システム”, 電子情報通信学会総合大会（新潟）（2014年３月19日）（a-3）

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