IEEE 802.16標準是針對無線城域網路(Wireless Metropolitan Area Network)而設計的，它支援服務品質(QoS)，而且具有相當高的傳輸速率。每一種應用服務都有不同的型態，根據這些不同的型態，802.16 定義了四個不同的服務品質類別。然而，最關鍵的部份－封包排程卻沒有被定義在802.16標準裡面。在這篇論文中，我們提出了一套完整的允入控管(call admission control)和上行封包排程的架構。首先，我們先以令牌桶(token bucket)機制為基礎，設計了一套802.16專用的允入控管和上行封包排程的模組。接著我們介紹如何將令牌桶機制套用至一般的連線。我們找出了一個預測連線的延遲(delay)和漏失率(loss rate)的模型，接著可以利用這個模型，並透過簡單的搜尋演算法來找出適合的令牌速率和令牌桶的大小。模擬的結果表示，我們的允入控管和上行封包排程能夠確實對具有即時性質的連線的提供保證，且我們將令牌桶機制套用到一般連線的模組也能準確的運作。最後，我們也提出了一個簡單的整合實例並評估其效能。 / The IEEE 802.16 standard was designed for Wireless Metropolitan Area Network (WMAN). It supports QoS and has very high transmission rate. According to different application types, there are four QoS classes defined in the IEEE 802.16 standard. The key part of 802.16 for QoS– packet scheduling, was undefined. In this thesis, a complete call admission control (CAC) and uplink packet scheduling is presented. We first proposed a token-bucket based uplink packet scheduling combined with CAC. Then a model of characterizing traffic flows by token bucket parameters, namely token rate and bucket size, is presented. We proposed a queuing model to predict the delay and loss rate for a token bucket controlled traffic flow. In order to fulfill token bucket based CAC, we need to find appropriate token rate and bucket size for any flows. A simple search algorithm coupled with our queuing model can be used to achieve this. Multiplexing of two traffic flows is also introduced. The simulation results show that our CAC and uplink packet scheduling can promise the delay requirement of real-time flows and prevent each class from starvation. The precision of our token rate estimation model is also validated. Finally, a simple integration of our CAC, uplink scheduling, and multiplexing is evaluated.

802.16與802.11e均有提供服務品質(QoS)，但是其MAC並不相同，為了達到QoS的保證，我們使用馬可夫鍊(Markov Chain)模型分析在不同連線數量時802.11e EDCA的延遲時間(delay time)。然後，我們可以再利用允入控制(CAC)機制限制連線的數量以保證延遲時間的需求，並使用令牌桶(Token Bucket)機制，在滿足延遲及頻寬的需求下控制輸出流量，在我們的令牌桶機制中可以依照頻寬需求的變化自動調整令牌(Token)產生速率，最後使用封包丟棄機制提升吞吐量(throughput)。 　　在提出我們的方法後，我們使用Qualnet模擬器驗證延遲時間、封包丟棄率及吞吐量，結果表示我們所提出的方法在三方面都有明顯的改進。 / IEEE 802.16 and 802.11e both provide Quality of Service (QoS), but the MAC of betweens is different. Ensuring the QoS guarantee, we use a Markov Chain model to analyze the 802.11e EDCA delay time under variance number of connections. Therefore, we can employ a CAC mechanism constraining the number of connections to guarantee the delay requirement. Further, considering the delay requirement and the bandwidth, we use a Token Bucket mechanism to throttle the traffic output that ensures the delay and bandwidth to be satisfied. And our Token Bucket mechanism can tune the token rate automatically by bandwidth requirement. Finally, we use the Packet Drop mechanism to improve throughput. After my methodology, we validate the delay, packet drop rate and throughput by simulator Qualnet. We have significant improvement in delay, drop rate, and throughput.

The increasing number of delay and loss critical services in packet networks require differentiated packet handling in the forwarding plane. Quality of Service (QoS) guarantees can be given for networks using resource reservation and admission control. However, such strategies require complex control plane extensions and might lead to higher operation expenditures. Network operators therefore often use over-provisioning and traffic differentiation to offer cheaper Class of Service (CoS) quality in their internet protocol (IP) packet networks. The number of differentiated classes and their autonomous system (AS) internal implementation is at the operator’s choice. This paper proposes a signalling concept for inter-AS layer three Class Set signalling, supported classes, their encoding and packet rate limitations. It makes use of the Border Gateway Protocol (BGP) as the predominantly used routing protocol for AS peering communication. The paper specifies two new nontransitive attributes, which enable adjacent peers to signal Class of Service capabilities and admission control limitations. The new "CoS Capability Attribute" and the “CoS Parameter Attribute" are simple data structures, which signal the classes, their per hop behaviour (PHB) ID code and the token bucket control performed at the ingress AS border router for rate limitation purposes. The denoted Class of Service forwarding support is meant as the AS externally available (transit) Class of Service support. The approach is now work in progress at the IETF.

The aim of this diploma thesis was to create an own DiffServ domain model, which is supplemented with stations generating various type of network traffic and implementation of token-bucket mechanism in router´s process model in Opnet Modeler simulation environment. DiffServ domain is made up from two edge and two core routers and includes servers and client stations generating VoIP, FTP, HTTP and database access traffic. It is described a process of distribution of traffic into different classes on edge routers of DiffServ domain along with assurance of separate handling with usage of an Assured Forwarding PHB mechanism. In point of differentiated packet processing is process model completed with generating of various statistics. The process of their creating is used to check a dropper activity, which is implemented together with token-bucket mechanism on ARP layer of the router. The functionality of the model is verified by simulation.

The increasing number of delay and loss critical services in packet networks require differentiated packet handling in the forwarding plane. Quality of Service (QoS) guarantees can be given for networks using resource reservation and admission control. However, such strategies require complex control plane extensions and might lead to higher operation expenditures. Network operators therefore often use over-provisioning and traffic differentiation to offer cheaper Class of Service (CoS) quality in their internet protocol (IP) packet networks. The number of differentiated classes and their autonomous system (AS) internal implementation is at the operator’s choice. This paper proposes a signalling concept for inter-AS layer three Class Set signalling, supported classes, their encoding and packet rate limitations. It makes use of the Border Gateway Protocol (BGP) as the predominantly used routing protocol for AS peering communication. The paper specifies two new nontransitive attributes, which enable adjacent peers to signal Class of Service capabilities and admission control limitations. The new "CoS Capability Attribute" and the “CoS Parameter Attribute" are simple data structures, which signal the classes, their per hop behaviour (PHB) ID code and the token bucket control performed at the ingress AS border router for rate limitation purposes. The denoted Class of Service forwarding support is meant as the AS externally available (transit) Class of Service support. The approach is now work in progress at the IETF.

The aim of this thesis project is to explore a network traffic regulator using bandwidth management techniques that regulates data traffic with the objective to use the network bandwidth to its maximum capacity while ensuring that the network is not overloaded. The bandwidth in the existing network architecture is shared between two co-existing, distinct data flows for on-board communication and diagnostic communication in an in-vehicle network. The diagnostic communication must not interfere with the more critical on-board communication and it should comply with the remaining bandwidth. In the existing solution, fixed delays are imposed on the data traffic which result in a waste of network capacity. The approach presented in this thesis uses two regulation algorithms for different types of diagnostic services. One regulation algorithm is activated for diagnostic services that require data segmentation and multiple data frames to accommodate the transferred data. This algorithm makes use of the Flow Control parameter Separation Time specified in ISO 15765-1:2011 "Road vehicles -- Diagnostic communication over Controller Area Network (DoCAN)". The other algorithm regulates diagnostic services that generate bursts of single frames where data segmentation is not required and it does so using traffic shaping techniques. The results in this thesis show that the network traffic indeed can be regulated for different diagnostic services by using the two mentioned regulation algorithms. The results also show that data is not lost due to high network utilisation and that the bandwidth is used to its maximum capacity without having to impose fixed delays on the network system. The regulator is adaptive in the sense that it can be used for different vehicle configurations with compatible network systems to ensure quality of service and a robust network system. / I detta examensarbete är målet att utforska en metod för att reglera  nätverkstrafik genom att använda tekniker inom bandbreddshantering  med syfte att utnyttja bandbredden till dess maximala kapacitet utan att överbelasta nätverket. Bandbredden i den nuvarande nätverksarkitekturen delas mellan två dataflöden för onboard kommunikation och diagnostisk kommunikation. Den diagnostiska kommunikationen får inte på någotvis störa onboard kommunkationen och får anpassa sig till den bandbredd som kvarstår. I det existerande systemet införs fixa fördröjningar i nätverkstrafiken vilket medför ett onödigt slöseri på nätverkskapaciteten och som också medför att de diagnostiska tjänsterna tar längre tid att utföra.  Tillvägagångssättet som presenteras i detta arbete använder två regleringsalgoritmer för olika typer av diagnostiska tjänster. En algoritm används för tjänster som kräver datasegmentering och flera dataramar för att skicka data. Den här algoritmen använder parametern Separation Time som är specificerad i ISO standarden 15765-1:2011 "Road vehicles -- Diagnostic communication over Controller Area Network (DoCAN)". Diagnostiska tjänster som istället genererar en skur av enstaka dataramar regleras med en traffic shaping algoritm som heter Token Bucket. Resultaten i detta arbete visar att det går att reglera nätverkstrafiken för olika typer av diagnostiska tjänster genom att använda de två utvecklade algoritmerna. Resultaten visar också att data inte går förlorat vid höga nätverkslaster och att bandbredden används maximalt utan att behöva införa fixa fördröjningar i nätverkssystemet. Regleraren är adaptiv i bemärkelsen att den kan användas för alla tänkbara fordonskonfigurationer med kompatibelt nätverkssystem för att försäkra quality of service och robusthet.