4G, 5G or 6G, all need wireless backhaul

A rose is a rose - or is there one that is sweeter?

Calling our networks 4G, 5G, or 6G makes little difference. What matters is service delivery to users. Once there is connectivity, the criteria for judging the efficiency of a network are speed, capacity, and latency (lag in response time). Our 4G experience is far short on these measures.  Improvements are possible if our government proceeds on the basis of (a) objective assessment, and (b) concerted action on systematic, realistic, and phased planning and execution.  The starting point is a factual assessment of our networks and service delivery compared with the rest of the world. The next steps are to frame policies and regulations to enable the better use of available resources for service delivery, without irrational hurdles.  

An aspect of telecom not obvious to users is the reality of layered technologies that exist even in advanced environments. For instance, a country with excellent mobile services such as Norway has achieved among the fastest average speeds of over 50 Mbps with continued investment in 4G networks.  4G has evolved considerably and provides the core network, except for Standalone 5G networks. 4G has latency down to two-digit milliseconds, and speeds comparable to 5G in the lower user bands (below 6 GHz). High-frequency 5G provides faster user access on 4G platforms.  
 

Realistically, we should plan for a mix of technologies going forward as 4G continues to evolve over the next decade.  However, we need policies that result in full 4G coverage of good quality, not merely indulgent talk. Also, while 3G is being phased out because of its less efficient use of spectrum, it will take years to transition fully to 4G and beyond because of the cost and scale. In Europe, for example, even 2G is to continue until 2025 for certain applications.  

What are the policies that can give us improved services? A good place to start is the Parliamentary Committee report tabled in February titled, “India’s Preparedness for 5G”.(1) Its main findings are that while 59 countries had deployed 5G, though largely on a limited scale, India had not done so. No 5G trials had been permitted as of January, and sufficient preparatory work had not been done. The challenges highlighted are:

• Inadequate spectrum, with only 50 MHz per operator, half the global average. For 4G, average spectrum per operator was even less, at a quarter of the global average.
• Exorbitant spectrum prices.
• Insufficient development of 5G use cases.
• Low fibre network availability.
• Deficient backhaul capacity.

The report emphasises the need for heavy investment to develop fibre networks, including for backhaul, and then deals with other aspects such as investments and local manufacturing.

Fibre does provide the best connectivity. While highly desirable, it is the gold standard, and often prohibitively expensive. Fibre connections to towers are ordinarily justifiable only when financially viable. Second, small cells have to proliferate for 4G, 5G, and 6G, with wireless or fibre links (backhaul) to networks and Wi-Fi user access.  The question is whether aiming for full or even substantial fibre connectivity to towers and small cells is realistic, compared with alternatives and technology trends.

Interestingly, the GSM Association published two reports addressing this in February 2021. The first was a study on backhaul in 40 countries titled, “Wireless Backhaul Evolution: Delivering next generation connectivity”.(2) The second was on the spectrum required for this titled, “Spectrum for Wireless Backhaul: GSMA Public Policy Position”.(3)

The first report indicates that 5G’s growing traffic and network capabilities will need massive augmentation of backhaul capacity through evolution.  Wireless links are estimated to constitute 65 per cent of global backhaul links between 2021 and 2027, evolving to higher frequencies with wider channels, with regulators’ decisions helping or hindering specific 5G markets.  The E-band (70-80 GHz) is expected to dominate wireless backhaul from 2021 to 2027.  Many countries are also using V-band (60 GHz) delicensed for Wi-Fi.  Even countries with high levels of fibre such as Japan and South Korea are using E and V bands for backhaul. Shouldn’t we do this, too? (See chart)

India has many urban and rural sites where fibre is infeasible, because of factors such as congestion, distance, terrain, dispersed users, and limited commercial potential. Wireless backhaul can fill in where fibre is not accessible or affordable, although evolution to higher, wider bands will be necessary.  Meanwhile, wireless V and E bands are now reasonable alternatives for distances of about 1 km, and 3-4 km or more, with the disadvantage of rain attenuation. The GSMA report suggests this could be mitigated with carrier aggregation (combining) of E-band with lower bands (such as 15, 18 or 23 GHz) to provide 10 Gbps links for up to 10 km.

Active network sharing

Regulators worldwide are considering or pursuing the substantial benefits of active network sharing for enhanced coverage, reduced costs, and faster deployment. A McKinsey report in 2018 cited network sharing becoming a standard model for mobile operators, with a reduction in the total cost of ownership by 30 per cent, while improving network quality.(4)

Steps for consideration

Formulate policies, laws and regulations for the following, with mandated spectrum/network sharing, paid for by reasonable revenue share (2-3 per cent) after a moratorium of 3-5 years (no auctions). Cap profits, and penalise diversion of revenues/profits.

1. Small cells: For Wi-Fi user access, V-band lower range and 6 GHz (using FCC model, as done for 5 GHz). Consider 12 GHz for Wi-Fi next.

2. Wireless backhaul, small cells/towers: V-band upper range and E-band, with light-licensed sharing among telcos for connecting to networks. 

3. Private networks, small cells and backhaul: V-band light-licensed for private networks, with public network connection through licensed telcos.

4. Active network sharing: Consider enabling or mandating active sharing of all elements of networks to speed up deployment, reduce clutter and radiation, and for efficient capital investment. 

Orchestration and coordination across government departments and consultation with industry as in NTP-99 to ensure better outcomes.

shyamponappa@gmail.com

https://eparlib.nic.in/bitstream/123456789/799780/1/17_Information_Technology_21.pdf 

2. https://www.gsma.com/spectrum/wp-content/uploads/2021/02/wireless-backhaul-spectrum.pdf 

3. https://www.gsma.com/spectrum/wp-content/uploads/2021/02/wireless-backhaul-spectrum-positions.pdf 

4. https://www.mckinsey.com/industries/technology-media-and-telecommunications/our-insights/network-sharing-and-5g-a-turning-point-for-lone-riders