Search

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.

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.