Comcast sidesteps open RAN debate with 5G buildout

Comcast is now beginning to connect some of its Xfinity Mobile customers to its 5G network in Philadelphia. But the company confirmed to Light Reading that the network does not currently use open RAN technology.

However, the situation stems mainly from the equipment Comcast is using from Samsung and does not necessarily represent a permanent block against open RAN.

Specifically, much of Comcast's 5G network in Philadelphia uses integrated, strand-mounted 5G transmitters from Samsung. Meaning, the equipment combines all of the necessary radio and processing components into one unit, and therefore does not need to employ open RAN interfaces among those components. Strand-mounted equipment is designed to rest atop Comcast's cable network in Philadelphia.

However, there are multiple vendors playing in Comcast's 5G network. For example, Comcast announced earlier this year it would use Nokia's 5G standalone (SA) core networking software to operate its network. That Nokia software will essentially control Comcast's Samsung radios.

Broadly, Comcast said it is working to keep its costs in check and reduce the complexity of its 5G network.

Variations of open RAN

Interestingly, Comcast is using the same basic vendors as Dish Network, a vocal open RAN proponent. 

Related:Comcast to use Samsung radios for 'selective' 5G network buildout

Nokia supplies Dish's 5G SA core, and Samsung is now Dish's main radio vendor. But Dish has made it clear that its network design is based on open RAN interfaces, which allow the company to mix and match vendors if it so chooses. Moreover, Dish's 5G equipment primarily sits atop standard cell towers, and therefore is not necessarily integrated in the way Comcast is pursuing.

Open RAN promises to separate RAN components into interoperable pieces, thus allowing different suppliers to connect their products together like Lego blocks. Such an approach represents a sea change to traditional, classical RAN architecture, which is typically supplied solely by a single big vendor like Samsung, Huawei, Nokia or Ericsson.

The open RAN trend promises to allow smaller, specialized vendors to insert their equipment into open RAN-capable networks. But bigger vendors can also implement the specifications into their existing equipment so that operators can have open RAN-compatible equipment supplied by a single vendor. 

For example, Verizon has indicated that it is now requiring some of its existing vendors to support open RAN specifications. And Ericsson recently said it would support an open RAN fronthaul specification starting next year.

Related:Comcast shares the wireless wealth with Nokia

But supporting open RAN interfaces is not the same as running a network that mixes and matches equipment from different vendors and connects through open RAN interfaces.

In pursuit of 5G

As for Comcast's 5G buildout, the company is hoping to use its 5G efforts to reduce its MVNO payments to Verizon. The company is already working to offload its Xfinity Mobile traffic onto its Wi-Fi network, and it's now essentially adding a 5G layer on top of that strategy to further reduce the traffic it sends onto Verizon's own wireless network.

Comcast purchased more than 800 3.5GHz CBRS spectrum licenses for around $459 million in 2021. Now, the company is using the spectrum to build a small-scale 5G network in Philadelphia. Comcast officials have indicated that it may expand its 5G effort to other cities as well. Comcast reported the addition of 316,000 mobile lines in its second quarter results, bringing its mobile customer base to a total of 5.98 million.