International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The 21st Century Live Play (21CLP) program is developing a mobile, low cost, wireless networking system that supports applications to provide a number of services for military use. 21CLP is a joint Defense Advanced Research Projects Agency (DARPA) and Central Test and Evaluation Investment Program (CTEIP) project. The Naval Undersea Warfare Center, Division Newport (NUWCDIVNPT), Code 382 has been assigned as the program manager for a T&E version of the 21CLP system. The 21CLP vision is a common instrumentation function that links, in real-time, live land, air and maritime entities together with a virtual battlespace in any location where forces are deployed or being trained, weapons systems are being tested and evaluated, and ultimately where missions are being conducted. This vision will be realized with an embedded, mobile, distributed, untethered system that requires little or no site preparation.

近幾年無線寬頻網路崛起，寄望WiMAX可以取代最後一哩，雖然WiMAX有QoS的設計，但是對於Call Admission Control、Bandwidth Allocation、Scheduler並沒有實際定義，給予廠商彈性設計。本篇論文提出以機器學習的方式依據網路狀態動態配置頻寬，以符合實際頻寬需求。 由於BS在配置頻寬的時候並沒有SS佇列的訊息，使得BS無法配置適合的頻寬，達到較好的效能，尤其是有期限的rtPS封包最為明顯。在系統負載較高的環境下，容易導致封包遺失提升，吞吐量降低的情形發生。因此本研究提出了支持向量機的方式，收集大量Training Data，訓練成動態頻寬配置模組；以動態配置適合的頻寬給rtPS，使rtPS在負載高的環境下的封包遺失率降低，且延遲能夠維持一定水準。搭配適應性頻寬配置策略，在低負載的環境下可以保留少許頻寬給Non Real Time Traffic，在高負載環境下，先滿足Real Time Traffic為原則。模擬工具採用NS 2-2.29、長庚大學-資策會的WiMAX模組，以及台大林智仁老師開發的支持向量機函式庫libSVM。 / In recent years, the rise of wireless broadband access networks. Hope that WiMAX can solve the last mile problem. Although WiMAX has QoS design, but for call admission control, bandwidth allocation, scheduler are not defined in standard. In this paper, we proposed a machine learning approach dynamic bandwidth allocation based on network state. BS because of the bandwidth allocation at a time when there is no message of SS’s queue. Enables BS can not configure a more suitable bandwidth to achieve better performance. In particular, there is the deadline of rtPS packets. At the higher loading on the system environment, easily lead to packet loss raise, lower throughput situations happen. In this study, a support vector machine approach to collect a large number of training data. Training modules into a dynamic bandwidth allocation. We can dynamically allocate bandwidth to fit rtPS. Adaptive bandwidth allocation strategy, at the low loading environment can keep some bandwidth for non real time traffic. At a high loading environment must first meet the real time traffic. We use Network Simulator 2-2.29, CGU-III WiMAX module, libSVM library.

Tjänster för strömmad media stiger kraftigt i popularitet, samtidigt som utbudet av denna typ av tjänster ökar. Internet protocol television (IPTV) med standardupplösning levereras redan till många hem, och högupplöst IPTV kommer att bli vanligt inom en relativt snar framtid. Mer avancerade tjänster, som tredimensionell TV och TV med fritt valbara vyer, står sedan på tur. Strömmad video är av naturen väldigt bandbreddskrävande, och denna utveckling kommer därför att sätta den befintliga nätverksinfrastrukturen på prov. Multicast är mer bandbreddseffektivt än unicast för scenarion där många mottagare samtidigt är intresserade av samma data, vilket är fallet med populärt direktsänt material. Anledningen är att mottagarna av multicast-sessioner delar på resurserna via ett gemensamt transmissionsträd, där ingen data sänds mer än en gång över någon gren. Användningen av multicast kan därför generera stora besparingar av bandbredd. Internetleverantörerna har dock inga riktigt starka skäl för att stödja multicast, vilket medfört att spridningen varit långsam. Vi föreslår att multicast-sessioner tilldelas mer bandbredd när det uppstår trafikstockningar i näten. Fördelningen baseras på antalet mottagare och datatakten som de erhåller, eftersom det är det som avgör graden av resursdelning. Vi anser att det är rättvist att ta hänsyn till detta, och kallar därför den föreslagna bandbreddsfördelningen multicast-favorable max-min fair. Vidare så presenteras två bandbreddstilldelningspolicyer som använder sig av olika mängd återkoppling för att uppnå fördelningar som ligger förhållandevis nära den föreslagna. Vi föreslår även två mekanismer för kostnadsallokering, vilka bygger på antagandet att kostnaden för dataöverföring ska täckas av mottagarna. De föreslagna mekanismerna fördelar kostnaderna mellan mottagarna baserat på deras andel av resursutnyttjandet, vilket generellt är fördelaktigt för multicast-mottagare. De två mekanismerna för kostnadsallokering skiljer sig åt genom att den ena eftersträvar optimalt rättvis fördelning av kostnaderna, medan den andra kan ge rabatt till vissa mottagare. Rabatten möjliggör större grupper med mottagare, vilket även kan reducera kostnaderna för icke rabatterade mottagare. Förslagen gör multicast mer attraktivt för användarna av strömmad media. Om förslagen implementerades i nätverk med multicast-stöd så skulle övriga Internetleverantörer bli tvungna att stödja multicast för att vara konkurrenskraftiga. / Media-streaming services are rapidly gaining in popularity, and new ones are knocking on the door. Standard-definition Internet protocol television (IPTV) has already entered many living rooms, and high-definition IPTV will become common property in the not too distant future. Then even more advanced and resource-demanding services, such as three-dimensional and free-view TV, are next in line. Video streaming is by nature extremely bandwidth intensive, and this development will put the existing network infrastructure to the test. In scenarios where many receivers are simultaneously interested in the same data, which is the case with popular live content, multicast transmission is more bandwidth efficient than unicast. The reason is that the receivers of a multicast session share the resources through a common transmission tree where data are only transmitted once along any branch. The use of multicast transmission can therefore yield huge bandwidth savings. There are however no really strong incentives for the Internet service providers (ISPs) to support multicast transmission, and the deployment has consequently been slow. We propose that more bandwidth is allocated to multicast flows in the case of network congestion. The ratio is based upon the number of receivers and the bitrate that they are able to obtain, since this is what determines the degree of resource sharing. We believe that it is fair to take this into account, and accordingly call the proposed allocation multicast-favorable max-min fair. Further, we present two bandwidth-allocation policies that utilize different amount of feedback to perform allocations that are reasonable close to be multicast-favorable max-min fair. We also propose two cost-allocation mechanisms that build upon the assumption that the cost for data transmission should be covered by the receivers. The mechanisms charge the receivers based on their share of the resources usage, which in general is favorable to multicast receivers. The two cost-allocation mechanisms differ in that one strives for optimum fair cost allocations, whereas the other might give discounts to some receivers. The discounts facilitate larger groups of receivers, which can provide cheaper services for the non-discounted receivers as well. The proposals make multicast transmission more attractive to the users of media-streaming services. If the proposals were implemented in multicast-enabled networks, the rest of the ISPs would be forced to support multicast, to stay competitive.

Tradicionalment, les tècniques d'accés múltiple en sistemes de comunicacions multi-usuari han estat desenvolupades o bé orientades a la connexió o bé orientades al tràfic. En el primer cas, l'objectiu és establir tants canals ortogonals com sigui possible per tal d'assignar-los als usuaris. Aquesta idea va motivar el disseny de les estratègies més conegudes, com són FDMA, TDMA i CDMA. Per altra banda, però, els mètodes d'accés aleatori que s'iniciaren amb el conegut ALOHA pretenen compartir estadísticament un mateix medi de comunicació aprofitant la necessitat de transmetre la informació a ràfegues que s'origina en les xarxes de dades. Així, molts dels actuals sistemes es poden encabir dins d'aquest esquema si a més a més, tenim en compte combinacions d'aquestes. No obstant, sistemes moderns com el DVB-RCS en l'entorn de comunicacions digitals per satèl·lit o el WiMAX en l'accés terrestre de banda ampla implementen mecanismes de petició i assignació de recursos, els quals requereixen una gestió dinàmica d'aquests en el sistema (és el que s'anomena distribució dinàmica de l'amplada de banda en un sentit ampli).L'anterior concepte inclou múltiples variables, configuracions i protocols tant de capa física com de capa d'enllaç. En aquesta tesi s'exploren en primer lloc les bases matemàtiques que permeten coordinar les diferents capes de la divisió OSI dels sistemes i els distints nodes dins la xarxa. Ens referim a les tècniques de descomposició focalitzades en problemes d'optimització convexa, els quals han aportat, durant els últims anys, solucions elegants a molts problemes dins dels camps del processament del senyal i les comunicacions. Revisarem els esquemes coneguts i proposarem una nova metodologia. Acte seguit, es comparen les diferents possibilitats de descomposició, cadascuna de les quals implica diferents maneres d'establir la senyalització. A la pràctica, són aquestes diverses opcions de descomposició les que infereixen les diferents interaccions entre capes o els protocols de control entre elements de la xarxa. Els resultats en quant a nombre d'iteracions requerides per a convergir a la solució òptima són favorables al nou mètode proposat, la qual cosa obra noves línies d'investigació.Finalment, es contribueix també amb dos exemples d'aplicació, en DVB-RCS i en WiMAX. Formulem el problema de gestió de recursos resultant de l'accés múltiple dissenyat per cadascun dels sistemes com un problema de maximització d'utilitat de xarxa (conegut com a NUM en la bibliografia) i el solucionarem aplicant les tècniques anteriors. L'objectiu serà garantir l'equitativitat entre els usuaris i preservar, al mateix temps, la seva qualitat de servei. Per aconseguir-ho, cal seleccionar funcions d'utilitat adequades que permetin balancejar l'assignació de recursos cap als serveis més prioritaris. Mostrarem que en els escenaris considerats, l'ús del mètode proposat comporta guanys significatius ja que requereix menys iteracions en el procés (i per tant, menys senyalització) o bé menys temps de càlcul en un enfoc centralitzat (que es tradueix en la possibilitat d'incloure més usuaris). També es mostren els avantatges de considerar interaccions entre capes, ja que es poden ajustar els paràmetres de capa física per tal d'afavorir els tràfics més prioritaris o bé extreure els requeriments de servei de valors típicament disponibles en capes superiors.En general, la implementació eficient de tècniques de gestió dinàmica de recursos treballant en l'accés múltiple dels sistemes pot aportar guanys significatius però implica establir una bona coordinació entre capes i elements de xarxa. L'eina matemàtica que ho possibilita són les tècniques de descomposició. Cada nou escenari i sistema introdueix un nou repte d'optimització i la capacitat que tinguem de coordinar totes les variables del sistema cap al punt òptim en determinarà el rendiment global. / Traditionally, multiple access schemes in multi-user communications systems have been designed either connection-oriented or traffic-oriented. In the first ones, the goal was to provide as many orthogonal channels as possible, each one serving a different connection. That is the motivation of the so-called FDMA, TDMA and CDMA solutions. On the other hand, random access techniques, which started with the so-called ALOHA protocol, aim to statistically multiplex a shared communication medium by means of exploiting the random and bursty nature of transmission needs in data networks. Most of the multiple access solutions can be interpreted according to that classification or as a combination of those approaches. Notwithstanding, modern systems, such as the digital satellite communications standard DVB-RCS or the broadband wireless access WiMAX, have implemented a multiple access technique where users request for transmission opportunities and receive grants from the network, therefore requiring dynamic bandwidth allocation techniques. The concept of dynamic bandwidth allocation is wide and involves a number of physical and link layer variables, configurations and protocols. In this Ph.D. dissertation we first explore the mathematical foundation that is required to coordinate the distinct layers of the OSI protocol stack and the distinct nodes within the network. We talk about decomposition techniques focused on the resolution of convex programs, which have elegantly solved many problems in the signal processing and communications fields during the last years. Known schemes are reviewed and a novel decomposition methodology is proposed. Thereafter, we compare the four resulting strategies, each one having its own particular signalling needs, which results in distinct cross-layer interactions or signalling protocols at implementation level. The results in terms of iterations required to converge are favourable to the proposed method, thus opening a new line of research.Finally, we contribute with two practical application examples in the DVB-RCS and WiMAX systems. First, we formulate the dynamic bandwidth allocation problem that is derived from the multiple access schemes of both systems. Thereafter, the resulting Network Utility Maximization (NUM) based problem is solved by means of the previous decomposition mechanisms. The goal is to guarantee fairness among the users at the same time that Quality of Service (QoS) is preserved. In order to achieve that, we choose adequate utility functions that allow to balance the allocation towards the most priority traffic flows under a common fairness framework. We show that in the scenarios considered, the novel proposed coupled-decomposition method reports significant gains since it reduces significantly the iterations required (less iterations implies less signalling) or it reduces the time needed to obtain the optimal allocation when it is centrally computed (more users can be managed). We further show the advantages of cross-layer interactions with the physical and upper layers, which allow to benefit from more favourable adjustments of the transmission parameters and to consider the QoS requirements at upper layers. In general, an efficient implementation of dynamic bandwidth allocation techniques in Demand Assignment Multiple Access (DAMA) schemes may report significant performance gains but it requires proper coordination among system layers and network nodes, which is attained thanks to decomposition techniques. Each new scenario and system adds another optimization challenge and, as far as we are able to coordinate all the variables in the system towards that optimal point, the highest will be the revenue.

The past decade has witnessed the fast development of peer-assisted video ondemand (PA-VoD) systems, which have attracted millions of online users. The efforts on improving the quality of video programs have never ceased since the beginning, and nowadays offering high-definition (HD) channels has become a common practice. However, compared with standard-definition (SD) channels, HD channels have to sustain a higher streaming rate to peers, which is a challenging task. In real systems, HD channels often suffer from poor streaming quality, or impose a heavy burden on the servers. This thesis conducts an in-depth study on peer cache and upload bandwidth management at the same time for multi-channel PA-VoD systems, where HD and SD channels coexist with different bandwidth and cache requirements. The objective is to minimize the server bandwidth consumption, and thus the maintenance cost of VoD service providers. The solution is cross-channel allocation (or view-upload decoupling), i.e., making SD channels help HD viewers with the surplus peer-contributed resources. The management of these resources includes bandwidth allocation and caching strategies. We first propose a generic modeling framework to capture the essential characteristics of PA-VoD systems: the demand and supply of bandwidth from peers. Our modeling framework can be customized or extended to model a variety of caching strategies, including FIFO, passive caching, and active caching with different user behaviors. We then apply the modeling framework to two representative scenarios: stationary scenarios, where the channels have fixed popularity; and non-stationary scenarios, in which a new movie is released, and peers enter the channel in a flash-crowd manner. We prove using our models that passive caching is efficient for stationary user behaviors, and derive the optimal caching solutions when the channels in the system demonstrate different popularity evolutions, i.e., with non-stationary behaviors. With the insights gained from our modeling work, we design effective centralized heuristic algorithms and practical distributed strategies for peer cache replacement and upload bandwidth allocation, with a near-optimal utilization of these resources. We propose centralized and distributed cross-channel allocation, and also extend the substreaming technique from live streaming to VoD systems, where it demonstrates its extreme feasibility. Our extensive simulation results verify the efficacy of these heuristic and practical strategies. / Graduate / 0984 / changlecsu@gmail.com

Access networks have been going through many reformations to make them adapt to arising traffic trends and become better suited for many new demanding applications. To that end, incorporating fog and edge computing has become a necessity for supporting many emerging applications as well as alleviating network congestions. At the same time, energy-efficiency has become a strong imperative for access networks to reduce both their operating costs and carbon footprint. In this dissertation, we address these two challenges in long-reach optical access networks. We first study the integration of fog and edge computing with optical access networks, which is believed to form a highly capable access network by combining the huge fiber capacity with closer-to-the-edge computing and storage resources. In our study, we examine the offloading performance under different cloudlet placements when the underlying bandwidth allocation is either centralized or decentralized. We combine between analytical modeling and simulation results in order to identify the different factors that affect the offloading performance within each paradigm. To address the energy efficiency requirement, we introduce novel enhancements and modifications to both allocation paradigms that aim to enhance their network performance while conserving energy. We consider this work to be one of the first to explore the integration of fog and edge computing with optical access networks from both bandwidth allocation and energy efficiency perspectives in order to identify which allocation paradigm would be able to meet the requirements of next-generation access networks.

No description available.

No description available.

隨著智慧家庭概念與技術的興盛與成熟，未來ISP(Internet Service Provider)業者勢必面臨管理大量智慧家庭中各種不同應用競爭頻寬資源的情況。為因應大量且繁雜類型的應用服務彼此競爭智慧家庭端及ISP端的頻寬資源，考量並應用適當的頻寬分配法則以盡可能優化使用者體驗(QoE)是本研究的研究動機。相關文獻的排程演算法如TDPSS (Time Domain Priority Set Scheduler)、MSCDL (Mac Scheduler)、Proportional Fair (PF)及Adaptive Modified Largest Weighted Delay First (AMLWDF)等。若要用以管理大量智慧家庭的頻寬資源時，ISP業者須將家庭申辦頻寬方案以及ISP端的系統頻寬分開考量。ISP在整合(aggregate)多個家庭的頻寬資源請求時，會依服務類別分配頻寬，最後依據不同類別採取適當處理，進而提升不同應用的QoS品質。 本篇論文著重於延遲時間的考量，提出能分類來自各個智慧家庭中，屬於不同 QCI (QoS Class Identifier)級別的頻寬請求並以不同佇列存放，依DADS (Delay Aware Dynamical Scheduling)演算法計算優先權值。我們利用保障頻寬與動態配置頻寬給不同用戶服務佇列，並優先分配頻寬給較高優先權的用戶服務，以期在維持一定公平性的前提下，盡可能地降低延遲來提升QoS品質。 在我們的實驗數據分析中，我們將DADS和其他方法如MSCDL、PF、TDPSS以及AMLWDF進行公平性、產能、延遲以及抖動率等效能優劣的比較與分析。最後在總結與未來研究方向，我們歸納與整理了DADS與PF、MSCDL、TDPSS以及AMLWDF等演算法的效能優劣。實驗結果顯示，在延遲上，DADS勝過PF和TDPSS，但略輸MSCDL及AMLWDF；在抖動率及產能上，DADS均較其它四者為差；公平性上則是劣於TDPSS、PF及MSCDL但優於AMLWDF。雖然DADS在整體的表現並非最好，但在特別重視延遲時間的Category1類別(包含QCI級別為1、2及5的應用服務)的延遲效能僅輸AMLWDF些許，而產能卻明顯勝過AMLWDF，由此可見DADS在Category1的表現最佳。 / With the concept and technology of smart homes becoming more and more mature and popular, Internet service provider (ISP) must face managing large set of various applications from smart homes which competing for bandwidth resources. In order to enhance Quality of Services (QoS) of a lot of various applications while they are competing bandwidth resources of both smart homes (home internal) and Internet service provider (home external), we propose a QoS aware bandwidth allocation criterion to optimize Quality of user Experience (QoE). Since ISP has to manage bandwidth resources of large set of smart homes, in the proposed criterion each ISP separates the bandwidth resources for home external bandwidth and system bandwidth of ISP, respectively. Then, aggregates bandwidth requests of large number of smart homes according to distinct service classes. This thesis focuses on the performance index of delay. We proposed to classify bandwidth requests from smart homes and put them into different queues, finally, calculate priority values by DADS (Delay Aware Dynamical Scheduling) algorithm. The proposed method is able to effectively reduce delay time with certain degree of fairness guarantee by dynamically allocate bandwidth resources for services with distinct service priorities. In the experiments, we compared DADS with other algorithms such as MSCDL (Mac Scheduler), PF (Proportional Fair), TDPSS (Time Domain Priority Set Scheduler) and AMLWDF (Adaptive Modified Largest Weighted Delay First), etc. in terms of fairness, throughput, delay and jitter. The experiments results show that DADS performs much better than PF and TDPSS but a bit worse than MSCDL and AMLWDF in terms of delay. However, DADS shows no better performance than all other algorithms in terms of jitter and throughput. In fairness comparison, DADS is worse than PF, TDPSS and MSCDL but is better than AMLWDF. Though DADS has no superior performance on overall indices, it is a bit worse than AMLWDF in delay of Category1 (including QCI 1, 2 and 5), its throughput is better than AMLWDF. Therefore, DADS’s performance is the best on Category1 considering overall indices.

Energy conservation in next generation Passive Optical Network system (NG-PON) has gained more and more attention. NG-PON system can not only deliver best-effort data traffic, but also real-time data traffic, e.g. voice and video, that have strict bandwidth, delay, and jitter requirements. To meet the energy and service requirements, a NG-PON system must have energy efficiency and differentiated QoS mechanism built in. Few research efforts have been reported on maximizing energy efficiency while maintaining QoS in the fairly new PON system design. We have extended the Upstream Centric Scheme (UCS-based) scheduling scheme idea into a novel QoS-differentiated energy-efficient PON system consisting of two main modules: firstly, the proposed differentiated QoS analytical model is described in detail to reduce the packet delay in the upstream traffic scheduling. The simulations further demonstrate the QoS metrics of the system: packet delay, bandwidth utilization, dropped packet rate, and queue length. Secondly, a novel analysis is proposed for downstream traffic scheduling with limited service discipline at Optical Line Terminal (OLT) side under the UCS-based Green Bandwidth Allocation (GBA) framework. We, first, derive the mean packet delay expression of this model. Then, the sleep time for each Optical Network Unit (ONU) is derived by setting identical upstream/downstream transmission cycle time. Based on the analytical model, an approach is developed to save the maximum energy in a dynamic PON system while without violating the delay requirement. Moreover, simulation is conducted to verify the developed analytical model and the proposed approach. In the end, considering the differentiated QoS and downstream traffic scheduling, an algorithm of the energy efficient scheduling scheme is proposed as well under the UCS-based GBA.