Abstract In this paper, we address the architecture and the procedures that can enable voice call handover from UMTS to WLAN and we also study how efficiently the WLAN can support the voice calls transferred from UMTS. Our study is based on a practical simulation model that lets us quantify the maximum number of voice calls that can be handed over from UMTS to WLAN, subject to maintaining the same level of UMTS QoS and respecting some WLAN policies. In addition, several other voice call performance metrics are derived. Our results indicate that an IEEE 802.11e access point can support a limited number of voice calls handed over from UMTS, which depends primarily on the applied WLAN bandwidth sharing policy (i.e., how the bandwidth is shared between WLAN voice and data users) and the QoS requirements. The performance of the WLAN scheduling algorithm is also of paramount importance and in our study we consider the so‐called ARROW scheduler. Although the simulation results are derived for a specific bandwidth sharing policy, they can readily be scaled and provide practical upper bounds for the number of UMTS voice calls that can be seamlessly admitted to a WLAN access point. Copyright © 2007 John Wiley & Sons, Ltd.

In this paper we present a novel traffic scheduling algorithm for IEEE 802.11e, referred to as ARROW (adaptive resource reservation over WLANs), which aims at providing improved performance for the support of multimedia traffic. The novel characteristic of this algorithm, compared to previous proposals, is that it performs channel allocations based on the actual traffic buffered in the various mobile stations, i.e., on the exact transmission requirements. This feature renders ARROW ideal for variable bit rate traffic. However, an enhancement is also presented that improves ARROW performance under constant bit rate traffic. The ARROW algorithm and its enhancement are discussed and evaluated against two other schedulers found in the open technical literature, namely the simple scheduler and SETT-EDD. Results from a detailed simulation model verify that ARROW provides much better channel utilization and considerably improved performance, in terms of mean delay and packet loss

In this paper we present a novel traffic scheduling algorithm for IEEE 802.11e, referred to as ARROW (adaptive resource reservation over WLANs), able to handle multimedia traffic. The novel characteristic of ARROW is that it performs channel allocations based on the actual traffic (not estimated traffic) buffered in the various mobile stations. Additionally, a variation of ARROW is studied for improving the performance for constant bit rate traffic. The ARROW algorithm and its enhancement are evaluated against two other schedulers found in the literature, namely the simple scheduler and SETT-EDD. Results from a detailed simulation model show that much better channel utilization and considerably improved performance can be provided.

The paper focuses on the integration of Internet and wireless LANs (WLANs) and proposes a novel technique that supports seamless and efficient integration. This technique is based on a generic adaptation layer, referred to as wireless adaptation layer (WAL), which is introduced between the IP layer and the WLAN link layer. WAL is designed to: (i) cope dynamically with wireless channel impairments; (ii) provide QoS interworking between the IP infrastructure and the WLAN; (iii) be independent of the WLAN technology. These characteristics account for the advantages of WAL, namely, improved performance, wide applicability and provisioning of differentiated services.

A centralized approach for dynamic channel assignment (DCA) in wireless ATM system is presented. The proposed approach applies to structured wireless ATM LANs, where base stations act as hubs to offer wireless access to mobile units. An intradomain DCA entity (IADCA) is introduced for the dynamic assignment of resources to the requesting base stations, taking into account mutual interference constraints and current resource usage. The IADCA entity is based on two different reservation disciplines and multiple assignment policies when candidate carriers are available. Simulation results for a number of scenarios are presented to assess the performance of the proposed approach.