Dietrich Hunold

Optimizing HSDPA performance in the UMTS network planning process

With HSDPA design and specification now being finished, the HSDPA will be ready for deployment in the very near future. While theoretical HSDPA performance has thoroughly been investigated, one of the major tasks of WCDMA network operators, the embedding of the HSDPA into their Release 99 network planning and optimization workflow, has rarely been treated so far. Consequently this paper presents and discusses a process and a toolset to find an optimal performance balance between Release 99 services and the HSDPA. Especially the availability of necessary input values for this process was noted in the process design, since, for example, traffic maps are usually not reliably available in the planning phase. Thus, for the first time the capacity of Release 99 services and the Release 5 HSDPA are jointly elaborated within one workflow and possible trade offs are pinpointed to. Hereby we concentrate on a discussion of the workflow rather than on presenting concrete planning results for a sample scenario.

Concept for universal access and connectivity in mobile radio networks

Mobile communications is characterized by a fast growing number of users and an increasingly heterogeneous data traffic due to emerging multimedia packet services. Likewise, users desire more mobility support, thus demanding permanent availability at any place and any speed. The conventional answer to this problem is building new wireless standards. But these standards require totally new hardware, users cannot use their old terminals, and no wireless communication among networks is possible which considerably constrains the availability demand. Instead, we propose a unified way for basic network access and connectivity maintenance. It is embodied by a perpetually available signalling channel-the network access and connectivity channel (NACCH) and a common functionality trunk, shared by several networks. With this concept, networks can communicate and, hence, form a mega-network where users have universal access and roaming support.

Integrated broadband mobile system (IBMS) featuring smart antennas

IBMS is a concept for future mobile communication systems to provide a large range of data rates with different degrees of mobility. The integration of heterogeneous services and communication systems requires a common Network Access and Connectivity CHannel (NACCH) for basic signaling to provide permanent network access. Smart Antennas are utilized to adaptively enable a trade-off between mobility and data rate.

A flexible mobility-aware transmission scheme utilizing smart antennas in a wireless cellular network

The properties of the radio transmission channel, and consequently the performance of a mobile radio network, are highly sensible to the movements of the users. The user behaviour influences the link quality, cell dwell times, handover rates, outage probability, etc. Existing networks as, e.g., the Global System for Mobile Communications (GSM) have a rather fixed structure. They can only adapt the modem to the permanently changing channel conditions, but are not able to reconfigure the network resources according to the mobility of the users. The Integrated Broadband Mobile System (IBMS) concept provides a trade-off between data rate and mobility by means of a set of transmission classes that use smart antennas in different configurations, including smart antennas at both the base and the mobile site. It is shown how capacity can be increased by switching between the classes according to the user mobility. If, however, a single transmission class is considered, smart antennas employed at the mobile terminal have a negative impact on the network capacity. It is demonstrated that this behaviour is inherent to the topology of a cellular network. But IBMS provides the potential to overcome this peculiarity due to its intrinsic structure.