Average access speeds for LTE subscribers under normal network load conditions at random locations within the coverage area are considerably lower than the 100 Mbps downlink and 50 Mbps announced by some operators.
Last week, PC World magazine published some results after having tested the most advanced mobile broadband technology from all the tier 1 operators across 260 locations in 13 US cities.
The results show Verizon’s LTE as the winner over T-Mobile’s and AT&T HSPA+ and Sprint’s Wimax, averaging 6.44 Mbps downlink and 5 Mbps uplink.
Considering the fever to get fiber to the LTE base station by some early LTE adopters, what are those tens of Gbps needed for? Today providing fiber backhaul to LTE sites is more related to a willingness to concentrate efforts on the RAN segment, discarding any backhaul issue at the expense of not fully using resources.
However, in the long term operators should take additional advantage of this backhaul capacity. In my opinion, innovations from vendors such as Alcatel-Lucent, with its LightRadio concept, and from operators such as China Mobile with its C-RAN architecture, are providing an answer.
Both LightRadio and C-RAN enable virtualized RAN: concentrating network baseband processing power from many cell sites into a few locations in order to lighten physical hardware needs at the point of radio delivery.
The higher computing efficiency of such central clusters would considerably reduce RAN power consumption, representing a high percentage of any operator’s power consumption (73% in the case of China Mobile).