Mobile networks are vital to building low-carbon economies and greener societies. Even with lower energy-efficient networks than 5G, they are still having a positive “enabling impact” on other industry sectors.
According to a report published in 2019 by the GSMA in collaboration with the Carbon Trust, entitled The Enablement Effect, the application of mobile technologies helped reduce CO2e (carbon dioxide equivalent) emissions globally by approximately 2.135 billion tons. The majority of avoided emissions stem from a decrease in electricity, gas, and fuel consumption.
The enablement effect is about ten times greater than the amount of CO2e emissions generated by the mobile sector, which, defined here, includes the energy to operate the networks, the embodied emissions of the networks, and the emissions of handsets.
But energy-efficiency innovation must continue, particularly in the RAN, which accounts for the bulk of mobile industry emissions. Carbon-reduction targets will not be met otherwise.
“For operators it is vital they improve energy efficiency if they are to meet their own carbon reduction emission goals and comply with targets set by the ITU and the GSMA, especially as traffic volumes increase with the introduction of 5G networks,” says Flora Miao, chief brand officer at Huawei wireless product line. “If operators do nothing, carbon emissions will only increase.”
Net zero targets…
In early 2020 the International Telecommunications Union (ITU), a United Nations (UN) agency, working in collaboration with the Global Enabling Sustainability Initiative (GeSI), the GSMA and the Science Based Target Initiative (SBTi), published a new ITU standard dubbed ITU L.1470.
ITU L.1470 is designed to set a pathway for ICT industry towards net zero emissions. According to the ITU, ICT industry must reduce its GHG (greenhouse gas) emissions by 45% between 2020 and 2030 if it is to comply with the Paris Agreement, which has a goal of goal of limiting global warming to 1.5°c above pre-industrial levels.
At the time of announcing the ITU L.1470 standard, the GSMA said 29 operator groups representing 30% of the world’s mobile connections were committed to the science-based targets. More have pledged alignment since then. As of April 2021, GSMA said operators covering 50% of mobile connections worldwide (and 65% of industry revenues) were now committed to science-based goals.
The GSMA, in 2019, also announced that it had set an industry goal to reach net zero emissions by 2025 at the very latest. It chimes with the same target set by the UN’s Race to Zero campaign, but across all industry sectors not just mobile. The GSMA noted in April that more than a third of mobile operators by revenue had met rigorous criteria set out by the Race to Zero initiative.
It’s a meaningful level of commitment. A 20% pledge for net zero emissions from any given industry sector, according to the UN campaign, can be seen as a tipping point — or “breakthrough moment” — when sufficient momentum is generated by a critical mass of key actors that enable the whole sector to break away from business as usual.
Given that the mobile industry was the first sector to pass the 20% milestone in January 2021, and which then jumped to 36% in a matter of months, the tipping point theory is well borne out.
…and how to meet them through hardware innovation…
Huawei has a multi-faceted strategy to assist operators in turbo-boosting energy efficiencies. A key part of that is rolling out high-capacity 5G networks supported by much more energy-efficient massive MIMO antenna configurations (32T32R and above) than is possible with today’s low-order MIMO found in 4G.
Using an innovative active antenna unit (AAU) blade, energy-per-bit efficiency (measured as cell-site power consumption divided by cell-site bandwidth) can increase dramatically. In a 32T32R antenna configuration using a 32T AAU, energy efficiency — at 0.13 Watt per Mbit/s — is 25 times greater than a 4G 2T2R rollout (3.3 Watts per Mbit/s). A 64T AAU deployment within a 64T64R antenna configuration, at 0.065 Watts per Mbit/s, is 50 times more energy-per-bit efficient when compared with 2T2R, which is typically limited to 150Mbit/s capacity.
Operators can have peace of mind when rolling out higher bandwidth cell sites using 5G and 5.5G to support soaring traffic volume — up to 5Gbit/s capacity in the case of 32T/32R and over 14.5Gbit/s at 64T/64R — that they do not hopelessly derail carbon-reduction targets.
Greater energy efficiencies can also be gleaned from deploying multi-channel and multi-band remote radio units (RRUs). “A multi-channel RRU has similar power consumption to legacy RF modules but has much higher capacity,” says Miao.
According to Huawei, a multi-channel RRU in an FDD 32T32R deployment can provide as much as five times the capacity of a 4T4R RRU, which means much greater efficiency (up to four times compared with legacy deployments). Huawei’s triple-band RRU, adds Miao, which supports 700MHz, 800MHz and 900MHz, can lower power consumption by up to 20% compared with legacy modules.
The streamlining and simplification of cell site deployments is another way to improve efficiencies. “In traditional cell site deployments, air conditioning typically accounts for 30-40% of energy consumption,” says Miao. “It means that energy efficiency for the whole site is around 60%, which is very low. By simplification, however, we can increase cell site efficiency to between 90% and 97%.”
One way to simplify is to cut down the number of cabinets. Using high-density modules, Huawei has shown it can reduce the number of outdoor cabinets from three to one and still support four bands. Another example of site simplification is to use a single energy-efficient blade, which is light and small. Huawei has demonstrated that up to 4500kWh in electricity can be saved each year, per site, using this approach.
…and software know-how
More energy-efficient hardware is not the only way to reduce carbon emissions from mobile networks. Software and clever algorithms, assisted by AI and machine learning, also has a key role to play.
Operators typically have between five and seven frequency bands, supporting multiple generations of cellular networks, and network inventory comprising both physical and logical assets. It’s very complicated to manage, which means network intelligence is required.
“AI-enabled optimal analysis can help reduce energy consumption by shutting network resources or even channels automatically when they are not being used, for example, while still ensuring stable KPIs,” says Miao.
Since 5G is much more energy efficient than legacy networks, it is an imperative for green-conscious operators to migrate traffic onto 5G as quickly as possible. “If the traffic load increased to 30% over the 5G network, cell site power consumption, according to our simulations, can decrease by 5%,” explains Miao. “If 5G accounts for 50% of the traffic load, power consumption can fall by as much as 18%.”
Hardware and software innovation surrounding 5G will play a starring role in enabling a low-carbon future.
This content is sponsored by Huawei. The Light Reading editorial staff has no involvement in producing sponsored content, verifying its accuracy or otherwise ensuring that it meets our editorial standards.