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We propose a novel and cost-effective approach for the deployment of third generation (3G) wireless systems over hybrid fiber coaxial (HFC) CATV networks. The main goal is to facilitate 3G deployment over the existing CATV plant and reduce the large cost required for building a dedicated last mile infrastructure for 3G access networks. Our proposal reduces the last mile cost by sharing the existing CATV network and using the standard equipment and protocols of data-over-cable systems interface specifications (DOCSIS). This allows rapid deployment of 3G wireless systems, facilitates convergence of wireless and wireline networks and paves the way towards all IP wireless networks. Enhancements to the DOCSIS medium access control (MAC) protocol must be implemented in order to support Quality of Service (QoS) guarantees for 3G data and signaling traffic. This paper presents the proposed 3G over CATV network architecture and DOCSIS medium access control (MAC) enhancements for enabling the support of QoS guarantees for 3G data and signaling traffic. The proposed MAC enhancements can reduce the access delay for delay-sensitive traffic by 30 to 40% over existing DOCSIS MAC without compromising QoS guarantees for other traffic classes, or the DOCSIS channel utilization. Copyright © 2004 John Wiley & Sons, Ltd.

Supporting real-time multimedia applications in any network requires scheduling techniques that can provide guaranteed delay and/or bandwidth to media streams. Coordinating access to the wireless medium in an IEEE 802.11 wireless LAN is different from network layer scheduling since it requires scheduling traffic flows in a distributed manner. We introduce a new scheduling framework called multiple access hybrid scheduling (MAHS) that utilizes the concept of virtual packet and emulates stations packets in the access point in order to centralize the scheduling process. This way the main scheduling function is performed solely in the access point thus enabling the use of conventional schedulers to for scheduling both uplink and downlink packets (hybrid scheduling). We deploy a modified version of weighted fair queuing (WFQ) as this internal scheduler. Performance evaluation and analysis of the proposed framework is described in this article.

We propose a cost effective deployment of Third Generation (3G) Wireless systems, and Wireless LANs (WLANs) over Hybrid Fiber Coaxial (HFC) CATV networks. WLANs and 3G networks are viewed as two wireless data technologies that complement each other in different environments. The main goal is to facilitates 3G/WLAN integration over the existing CATV plant, and reduce the huge cost for building a dedicated last mile infrastructure for 3G and WLAN access networks. For example, the last mile infrastructure cost for 3G systems accounts for more than 20% of a 3G system total cost. This is a major cost considering the tens of billions of dollars to be invested in 3G networks world-wide. Our proposal reduces the last mile cost by sharing the existing CATV network, and using the standard equipment and protocols of Data-Over-Cable Systems Interface Specifications (DOCSIS). This allows rapid deployment of wireless data systems, facilitates convergence of wireless and wireline networks, and paves the way towards all IP wireless networks. Special features and enhancements to DOCSIS Medium Access Control (MAC) protocol must be implemented in order to support Quality of Service (QoS) guarantees for Wireless users' data and signalling traffic. First, we conduct a traffic study for estimating the wireless data traffic loads in different geographical areas. We use the results of this study to ensure that CATV networks have adequate capacity for supporting wireless data users in addition to the existing services like CATV broadcasting and high-speed Internet access. The traffic study results are also used for mapping wireless network elements to an HFC CATV network. Second, we define a network architecture for deploying 3G systems over HFC networks. We identify the required components and functionalities for 3G over HFC deployment. Rather than defining a generic 3G/HFC architecture, we choose to define a specific 3G/HFC deployment. We select deploying 3G Universal Mobile Telecommunications System (UMTS) over DOCSIS CATV networks. Also, we define the required protocol stack for our UMTS over HFC deployment. Despite our specific UMTS over HFC deployment, our proposal can be extended to integrate other wireless data networks. Third, we propose a network architecture for interworking WLANs and UMTS networks over , DOCSIS CATV networks. The proposed architecture is independent of the WLAN/ 3G coupling chosen (e.g., loose coupling, or tight coupling). Different WLAN/ 3G interworking scenarios can be accommodated. We identify the network elements needed, and define the protocol stack for our deployment. Fourth, we present a QoS framework for DOCSIS CATV networks. The proposed QoS framework identifies, and discusses the required QoS functions in DOCSIS Cable Modem Termination System (CMTS), and Cable Modems (CMs). These functions are proposed for deployment in the upstream, and the downstream of DOCSIS transmission plane. Fifth, we present an implementation of DOCSIS MAC protocol that facilitates the proposed 3G/HFC deployment. Also, we enhance the DOCSIS MAC protocol with features that enable it to support QoS guarantees for multiple traffic classes. We focus on real-time traffic that requires very strict delay guarantees. The proposed MAC enhancements can be used for supporting real-time wireless traffic as well as other real-time wireline Internet traffic. Performance analysis for the proposed MAC protocol shows that QoS guarantees for real-time traffic is assured. Sixth, we propose a Weighted Fair Queueing (WFQ) based MAC Scheduler for DOCSIS networks. We identify scheduling at the MAC layer as crucial for QoS guaranties for both wireline and wireless traffic. Our WFQ scheduler guarantees QoS for both wireline and wireless traffic. Real-time traffic is provided with QoS guarantees without sacrificing QoS for other traffic classes with less stringent QoS requirements.

The interconnection of dissimilar LANs and devices over a high-speed backbone network can create congestion at a destination LAN (output) gateway when more than one device or LAN attempts to simultaneously communicate with the same device or LAN. The authors address the issue of congestion avoidance in LANs interconnected by a high speed backbone. A congestion-avoidance scheme that requires input gateways to secure permits to the output gateway before transmitting is proposed. An implementation of the proposed congestion-avoidance scheme in an ATM (asynchronous transfer mode) switch is shown. Performance results indicate that packet dropping rates are greatly reduced. >

We address the issue of supporting isochronous ATM traffic (e.g., real time (RT) voice traffic) over IEEE 802.14 based hybrid fiber coaxial (HFC) access networks. We propose a network architecture for a multi-service HFC network that can be used to support multiple services such as voice telephony and Internet access. Also, we propose enhancements to the 802.14 medium access control (MAC) protocols to facilitate supporting isochronous asynchronous transfer mode (ATM) traffic over HFC networks. In particular, we propose enhancements to the constant bit rate (CBR) service of 802.14 MAC protocol. We show that good quality of service, and enhanced bandwidth utilization are achieved using the proposed scheme. Our proposal facilitates the migration towards end-to-end ATM networks.

We propose a cost effective deployment of personal communications services (PCS) over hybrid fibre coaxial (HFC) CATV networks. Our proposal utilizes the emerging IEEE 802.14 network architecture and the medium access control (MAC) protocol. This paper presents the proposed network architecture and addresses some PCS mobility issues such handoff (HO), and location registration and update.