Quantitative analysis of split base station processing and determination of advantageous architectures for LTE

Centralization of the baseband processing in radio access networks may reduce radio site operational costs, reduce capital costs, and ease implementation of multi-site co-ordination mechanisms such as CoMP (coordinated multipoint transmission and reception). Initial architecture proposals for a centralized LTE deployment using transport of radio samples however require a high-bandwidth, low-latency interconnection network. This may be uneconomic, or may only be cost effective in a minority of sites. To mitigate that deficiency without sacrificing the benefits of centralized processing, we identified alternative interfacing options between central and remote units. To do so we analyzed possible splits of the Long Term Evolution (LTE) baseband processing chain for their bandwidth and latency requirements. Next, we analyzed operation impacts of potential splits based on a number of criteria including ease of CoMP introduction, possibility to realize pooling gains, and ability to update the system and introduce new features. Based on the results, we propose architectures with most of the benefits of centralization at a much reduced cost.