The Coming 5G Backhaul Challenge

Can we really expect three or more 5G networks?

As visions of 5G networks (public, corporate, campus, etc.) proliferate, the question of how many public 5G networks will be viable is being largely kept from public view.  In the U.S. three 5G networks are assumed—AT&T's, T-Mobile's and Verizon’s. DISH is building a fourth and the Pentagon has announced number five. In Japan Softbank, DoCoMo and KDDI have launched 5G networks, with Rakuten's in process.  In the UK four 5G networks are running.  Four also in Hong Kong, four planned in Taiwan and five in Thailand.

Mainland Europe is proceeding less dramatically—only two live networks in Germany to date plus one being tested, two in Italy with one to come, two in Poland with two others in test mode.  In France four networks are being developed.  In China, on the other hand, where 5G progress has been swift, a dual network approach is being adopted.  600,000 or more 5G active transceivers are projected for the end of this year.  So how come only two networks when China has three mobile operators?

China may be facing reality.  It has decided to have two operators, China Telecom and China Unicom, share a 5G network, while the largest operator, China Mobile, builds its own with some help from China Broadcast Network, the TV distribution entity.  Why is this China's reality?  Not only due to the number of cell sites involved but also due to the disruptive intricacies and costs of the backhaul networks.  Take Shenzhen where 46,000 5G cells operate today; all need sites and connections via fiber links and the core network.

Meanwhile, in South Korea a 5G sharing plan is being worked out initially for rural areas.  But even in cities where utility poles have been done away with and not universally replaced by as many lighting poles or where ducts are old, the challenges of 5G activation are daunting.  So how to diffuse 24, 26 and 28 GHz signals to every neighborhood? 

One idea is to have a single 5G network, operating at the wholesale level. The notion has been growing with development of OpenRAN technology as well as suggestions that a single “neutral” 5G network should be adopted (in Brazil, for example).  Most of the focus has been at the radio access level and is aimed at reducing the number of transceivers and sites involved in using millimeter band spectrum, especially where utility poles have been done away with or cost much to access and other “street furniture” is limited.  The backhaul challenge is also great, with MNOs often reluctant to share facilities.

So forget the 1G story of linking six to ten macro cell sites, found on tall, easily targeted towers. And the 4G one (MIMO or no MIMO) of a thousand towers covering a metro area. The fiber links and pico sites called for by 5G millimeter-band deployments will strain today's facilities beyond belief.  China will have a million 5G sites operating by mid 2021, mostly served by mid-band base stations. It could end up with 20 or 30 million sites or more, once millimeter spectrum is fully activated.

Then how will each operator—in a large four operator market—connect its 5G pico sites? The issue may come down to planning for a two backhaul network world for minimum redundancy and competition purposes or ending up with one or two networks through market consolidation.  Take your pick.