WCDMA AND WLAN FOR 3G AND BEYOND
with different QoS requirements having a maximum bit rate of 2 Mb/s. In order to satisfy the technical enhancements are being studied and standardized for WCDMA in 3GPP. Even with evolved WCDMA, there is a need for another enable smooth online access to corporate data services in hot spots. This need could be fulfilled by WLAN together with a high-data-rate cellular WCDMA system. WLAN offers an interesting possibility for cellular operators to offer additional capacity and higher bandwidths for end users without sacrificing the capacity of cellular users. The evolved WCDMA air interface will provide better performance and higher bit rates than basic WCDMA, based on first releases of the specifications. Eventually, evolution may not be the answer to all the needs, and some revolutionary concepts need to be considered. capabilities that by far exceed those of 3G systems like WCDMA. Judging from an application and factor between 3G and 4G will still be the data rate. We could define that 4G should support at least 100 Mb/s peak data rates in full-mobility wide area coverage and 1 Gb/s in low-mobility local area coverage. Other possible characteristics of 4G need to be further studied.
WCDMA was initially proposed and engineered with a vision that already has shown its futureproofness. WCDMA was designed to be a highp e r f o rma n c e s y s t em a b l e t o s u p p o r t f u t u r e applications requiring simultaneous transmission of several bitstreams that require individual quality of service (QoS). The original design choice seems to be well aligned with the future, where all applications and services can be carried over IP networks using IP protocols. This trend favors new applications where mobile users have several para l l e l ongoing s e s s ions ba s ed on one or s e v e r a l applications. At the same time WCDMA is already developing beyond original 3G technology targets, far outperforming any other wireless technology. F u r t h e rmo r e , t h e p o s s i b i l i t y t o c omp l eme n t WCDMA coverage and capacity wireless LAN (WLAN) solutions will be discussed briefly. Even though WCDMA is exceeding its initial capability targets, there is still a need for a quantum leap in air interface development in the longer term. The quantum leap can be seen as the fourth generation (4G). What this quantum leap is and when it could happen will be briefly discussed.
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