With the rise of technologies like 5G and Wi-Fi 6, it has all but been confirmed that the future is moving toward wireless infrastructure. Almost every computer-embedded handheld device features some kind of wireless connectivity; cellular, Wi-Fi, Bluetooth, and radio are among the most common ones. The whole networking infrastructure is termed Information and Communication Technology (ICT), which is one of the most critical technology sectors of recent times. One of the primary applications of ICT is telecommunication networks, which is the fundamental block behind the existence [foundation?] of all smartphones in the world.
Currently, network infrastructure accounts for a significant amount of the energy footprint in ICT. It is estimated that ICT is responsible for 2-4 percent of global carbon emissions. Also, the number of Internet users is increasing at a very rapid pace, with more than 5 billion active users, and is expected to increase by 300 million more in the next year. As a result, there will be a projected rise in the demand for electricity. Thus, energy efficiency will be one of the top priorities for wired networks and service infrastructures, followed by optimized planning of the deployment of wireless technologies like 5G.
There have been consistent research efforts that have analyzed the current consumption of network equipment and come up with solutions for minimizing power consumption without compromising the quality of service. By employing energy-saving strategies in ICT, around 15 percent of the global carbon footprint can be reduced, and a few of these strategies are discussed below.
Hibernating or Switching Off a Part of the Network
Telecommunication networks are currently built to withstand peak demands, and very little attention is paid to medium- and light-load scenarios. So a network that can switch off components when demand is low will be more adaptive and use less electricity overall. One of the strategies for achieving it is to use dynamic topology optimization, which is very effective when the off-peak load demand is less than 50 percent of the peak demands. This strategy satisfies the current load demands by selecting the topologies with minimum power consumption out of the multiple available topologies.
A similar strategy called dynamic bandwidth allocation is also used for fixed-line access types of networks. This allows users to have higher bit rates, while on the same medium, lower bit rates can also be provided to users who require it. These strategies are being employed in LTE-Advanced, the successor to LTE with advanced repeaters. The Quectel EM06 from Quectel Wireless Solutions is one such LTE-Advanced-based product and is optimized specially for M2M (machine-to-machine) and IoT applications. It features an M.2 form factor and can deliver speeds up to 300Mbps downlink and 50Mbps uplink data rates.
Traditional repeaters are always on, which amplifies or regenerates the signal from a base station to increase the network range. With advanced repeaters, the network can control and activate the repeater only when a user is within its range.
Optical Bypass
Switching off the individual components, as discussed above, saves a considerable amount of energy, and with a few other techniques, more energy savings can be achieved for the ones that are running. One of these techniques is optical bypass, which is already in use for reducing the load on the running components and reducing cost. The main router only processes the traffic intended for the intermediate node, and the rest of it remains in the optical link. For this purpose, optical add/drop multiplexers (OADMs) are used to switch the light’s path so that the input fiber links directly with the outgoing fiber link. FWSF-M/D-1310/CWDM-LC from Finisar is one such OADM that supports a single-channel input and features a 1310nm LC Connector.
Optical bypass eliminates the optical-electrical-optical (OEO) conversions at each node by using the optical cross-connect (OXC) or OADMs. Power-efficient grooming algorithm (PEGA) is used to decide the split of light path by analyzing the power consumption of network components like routers, optical amplifiers, transceivers, etc. This way, the capacity of the router can be reduced, thereby reducing the overall cost and power consumed. By utilizing the optical bypass technique, up to 45 percent of energy usage can be reduced.
Adaptive Link Rates
Another way of reducing the load on running components is to use adaptive link rates on the network lines. With this, multiple link rates with lower and higher speeds are supported on a single link. Users whose demand is satisfied with lower link rates save more on the energy consumed, and this strategy is already showing its potential in home gateways. One such product that can use this strategy is the PEF22622FV1.4 from Intel. It is an SDSL one-chip rate-adaptive transceiver with an embedded start-up. It supports all data rates from 144 kBit/s up to 2.3 MBit/s in steps of 8 kBit/s.
However, heavy users who require higher link rates of up to 10 Gb/s might not see much difference as the power consumption will always be on the higher side. This strategy will also have less effect on core networks since the amount of traffic dealt with is always constant and shows fewer variations.
Hybrid Optical Switching
Places like data centers, which constantly deal with a huge amount of traffic, are one of the most power-hungry components in ICT due to the huge scale of their deployment and 24x7 operation. There is a huge potential for power-saving in data centers, and research shows that by using hybrid optical switching (HOS), up to 32 percent of energy savings can be achieved. HOS combines optical circuits, burst, and packet switching on the same network. Depending on the application, the HOS-based network can be tweaked to the optical transport mechanism that best suits the requirements of the data centers.
HOS consists of two parallel optical switches to reduce power consumption and, at the same time, increase network performance. The first one is a slow and energy-efficient switch with long bursts, while the other is a fast switch with short bursts for transmission. This is a flexible strategy that can be integrated into the current infrastructure quickly without any major modifications.
Conclusion
Telecommunication is one of the fastest-growing sectors with a massive scope for energy savings. With the introduction of 5G, many strategies can be used to perform energy optimization and increase energy efficiency. Gateways in home networks are also incorporating these strategies as they hold a considerable share of power consumption in residential areas.
