By: Wolfgang Weber

Over 80 percent of mobile calls and data usage today occur indoors. The demand now is for reliable services and connectivity inside buildings in order to provide the same Quality of Experience (QoE) for bandwidth-hungry applications no matter where a user is. In an ecosystem where demand for traffic capacity is extremely dynamic and where provisioned wireless capacity is static, traditional network architectures require a degree of over-provisioning – up to 30 percent extra capacity – to ensure that peak demand will always be met. This business model is not ideal because it implies a systematic waste of resources which makes it challenging for network operators to realize OPEX and CAPEX savings.

DAS and small cells need more ‘intelligence’

Several technologies exist to address the issue of indoor wireless connectivity, each with different pros and cons. For a while, distributed antenna systems (DAS) and small cells have been the go-to approaches but they’re not without restrictions.

DAS provides indoor network capacity and coverage by enabling radio resources to be distributed throughout a venue. During the implementation process, network designers have to spend massive amounts of time and resources in the planning phase, taking into account a wealth of aspects from cabling requirements and support for single- or multi-carriers, to architectural and aesthetic considerations. DAS is able to accomplish what it’s originally created for and just that – to distribute wireless resources within a service area. Its static allocation of capacity between base stations and antennas and inability to dynamically provide network resources where and when they are needed makes DAS an inflexible solution that doesn’t maximize OPEX and CAPEX savings because operators are still required to over-provision for optimal QoE.

Alternatively, small cells may be simple and relatively inexpensive to implement – initially – but the technology racks up considerable OPEX due to the need to deploy massive quantities of them. Even with the sheer number of deployed small cells coexisting in a service area, each individual cell is unable to share network resources with one another. Although small cells have a multitude of applications – from the home, to outdoors for public users, and within an enterprise for indoor users – the associated costs of configuration and post-deployment management and maintenance deem small cells a costly, resource-intensive, and complex technology which doesn’t solve problematic over-provisioning.

The promises of cloud RAN

In addition to addressing provisioning concerns, mobile operators also have to consider cost efficiency, operational simplicity, flexibility, and scalability when aiming to manage their networks effectively. At the current stage of technological evolution, a cloud RAN (C-RAN) architecture is meant to address these considerations by providing benefits in operational costs and improving network manageability. The concept of C-RAN is the separation of the radio and antenna from the digital baseband and pools baseband units for multiple cells in a central location. This pool of baseband resources can be linked by fiber to radio heads at the antenna location. While C-RAN improves efficiency for the baseband resources, it still does not remove the need for over-provisioning on the radio resources.