The carrier says the trials will help guide its 5G standards contributions with the 3GPP. That standards body is projected to issue its first-phase 5G standards in 2018. The carrier is moving forward with 5G in such a way that it can “pivot” to compliant commercial deployments once 5G technology standards are set.
But otherwise, its 5G roadmap is pretty sketchy at this point, leaving us to speculate how the carrier might be working with Ericsson and Intel.
Last week, Ericsson announced its Elastic RAN, which enables the coordination of all the baseband units across a mobile network. Although Elastic RAN will support tight coordination between adjacent cell sites, those sites still must be connected by fiber. Each site coordinates with all its neighbors in a full peer-to-peer relationship.
One hypothesis is that millimeter waves could be used in place of fiber in a distributed 5G architecture. The millimeter-wave region of the electromagnetic spectrum is within the extremely high frequency range of 30 GHz to 300 GHz. The short range of millimeter waves can only be used for terrestrial communication over about a kilometer.
As far as its work with Intel, that will involve chips, obviously.
At last year’s Mobile World Congress, Cavium was showing a chip called the 7400, which keeps the baseband’s Layer 1 processing in the cellular modem, but frees up the baseband’s Layer 2 and 3 processing to go into the cloud. This lessens the bandwidth load, currently handled by fiber. AT&T could be working on something similar with Intel.
AT&T says its leadership in SDN gives it a headstart in 5G. In 2014 the carrier announced its plan to virtualize 75 percent of its network by 2020, and it expects to reach 30 percent virtualization this year. It has 14 million wireless customers on its virtualized network now.
AT&T’s goals for 5G are in line with other wireless stakeholders: speeds 10 to 100 times faster than today’s average LTE connections and latency in the range of 1 to 5 milliseconds.