Carriers Get Ready for HetNets, LTE-A, and Multicasting

With a limited amount of spectrum available to support burgeoning network traffic, wireless operators are readying a variety of technologies to maximize their use of existing spectrum holdings. These include HetNets, LTE-Advanced and multicasting.  

So what do all these terms mean and how will they help carriers operate their networks more efficiently?

 HetNets

HetNets aim to reduce traffic on cellular networks by using small cells and Wi-Fi. Small cells have shorter range than traditional macrocells and are intended for use in high-traffic areas. In theory each small cell could provide the same capacity as a macrocell. And because small cell ranges are shorter, the same spectrum can be re-used multiple times by a cluster of small cells covering the same territory that previously would have been assigned to a single macrocell.

Wi-Fi offload helps conserve spectrum by shifting traffic off of cellular networks onto Wi-Fi infrastructure operated by the carrier or someone with whom the carrier has a business relationship. The Hotspot 2.0 standard aims to enable traffic to shift seamlessly from cellular to Wi-Fi and to enable carriers to use one another’s Wi-Fi infrastructure.

A good source for more information on HetNets is a white paper from Ixia:  http://hetnet.ixiacom.com/

LTE-Advanced

LTE-Advanced (LTE-A) aims to boost mobile data bandwidth and increase the number of simultaneously active subscribers. At least one carrier – SK Telecom – already has deployed LTE-A. And several U.S. carriers have plans to deploy LTE-A this year.

One of the ways LTE-A boosts bandwidth is through spatial multiplexing -- also known by the acronym MIMO (for multiple inputs- multiple outputs). This works by using multiple antennas as transmitters and multiple antennas as receivers, thereby enabling multiple data streams to use the same frequency and the same timeslot.

Another important concept for LTE-A is carrier aggregation, which enables spectrum from different bands to function as a single wider band when needed and when the end user has a device that can work on all of the frequencies.

LTE-A also supports relay nodes, which are low-power base stations that enhance capacity at the network edge.

Additional information on LTE-A can be found in this extensive post from 3GPP.

Multicasting

Multicasting targets multi-media traffic, which is driving much of the growth in mobile data usage. Currently if two different users request the same video content, separate data streams are sent to each user. Multicasting aims to minimize traffic on mobile data networks by enabling a single data stream from the source to be shared by multiple end users, with each user getting its own feed only from a node near the network edge.

Multicasting is another technology we should expect to see some U.S. wireless carriers rolling out this year.

A good source for additional information about multicasting is, “LTE Broadcast - A revenue enabler in the mobile media era,” from Qualcomm.

2014 is shaping up to be a big year for wireless technology enhancements – and they’re just in time to help alleviate the spectrum crunch.