ENERGY EFFICIENCY REVIEW WITHIN OUR KENYAN TELCOS.

It is a worldwide goal to reduce energy consumption and CO2 emissions. The EU has targeted a reduction of 20% for year 2020 and just the other week we saw an MoU between Safaricom and UN signed championing for SDGs set.. A part of this energy reduction scheme concerns the    telecommunication industry and ICT that participates in a direct, indirect and systematic way.  Characteristic  examples which are yet to be in full use or are at nascent stages in our country  are  green networks,   smart   buildings,   smart   grids,   Intelligent Transportation Systems (ITS), energy efficient electronics (OLEDS, photonics, nanotechnology) and the application of  embedded  systems  towards  low  carbon  and  energy efficient technologies .

Telecommunication networks constitute a major sector of ICT and they undergo a tremendous growth. Capacity issues and delivery of complex real time services are some of the main concerns that yield high power consumption patterns. In our increasingly competitive mobile telecommunication sector, operators are turning to emerging markets for their next step growth situation that increases the number of subscribers and required base station equipment-case examples include safaricom now on 4G+ while Telkom is rolling our 4G across its country’s network footprint. This creates the need for equipment installation to areas where off grid renewable energy solutions are required and energy efficient networks are important e.g. Northern parts of Kenya. In addition, the increase of fuel and electricity costs bounds the OPEX of the system.

Telecommunication networks and broadband access are proved to consume a huge amount of energy for data delivery.  In general, the telecommunication   sector accounts for approximately 4% of the global electricity consumption (I researched widely from ITU web links).  I personally believe that  reduction  of  CO2   emissions  can  be accomplished  by  focusing  on  innovative telecommunication services like online taxation, video conference,   online   billing   that   can   enable   a   green economy. The goal is to deploy telecommunication networks enabling power efficiency, yielding a small ratio of required Watts per Gbps and Watts per user. Green initiatives have already been commenced by different operators around developed countries.

 This summarized word press discusses and proposes various energy efficient techniques for the green operation of telecommunication networks. Cellular networks that suffer most of the power waste nowadays are what I will highlight briefly. It is observed that almost 50% (including the operation of servers) is due to the operation of telecommunication networks. These can be mobile networks, WLANs, LANs and fixed line networks. As  far  as  the  overall network  performance  is  concerned  the  energy consumption is higher at the access part of the network and the operation of data centers that provides computations, storage, applications and data transfer in a network. On the other hand, backbone and aggregation networks present lower energy demands. This makes clear that an energy efficient architecture should focus on intelligent and efficient access techniques and efficient operation and data manipulation by data centers. The main functionalities of a network can be summarized as the process of regeneration, transportation, storage, routing, switching and processing of data. The power consumption patterns of these processes can be observed that the largest part of energy is consumed for routing/switching, regeneration and processing of data. Both communication protocols and electronic devices are responsible for this consumption and this imposes challenges for more sophisticated transport techniques, thermal removal from switches or the servers and less redundant data transfers.

 For mobile networks, a crucial factor affecting network power consumption is the site operation that incorporates base station equipments. . It is obvious that the greatest portion of energy is consumed for cooling of equipments and base station operation. Monitor operation and lighting requires the minimum of energy whereas for the backhaul energy consumption the picture is not clear and depends on the type of connections of the backhaul network (fiber or cable).  Within the base stations, high power demands are due to feeders (transmission of radio waves), the RF conversion units and power amplifiers, signal processing units and various electronic   equipments   such   as   air   conditioners   and auxiliary equipments.

 The power consumption within a base station exhibits important similarities with data centers. The available power from the electricity grid, the battery backup unit or the renewable energy (RES) enters the base station and is divided into an in-series path and an in-parallel path. Non- critical equipments support the operation of the IT equipments that are divided into radio units and baseband units. The most energy consuming devices of base stations are the cooling infrastructure, power amplifiers, RF feeders and the AC/DC and DC/DC conversion units. Depending on the number of sectors, nSC, and the antenna number, nTX, of the base station, the total power consumption is computed as follows;

 

In the above formula an additional factor models the power consumption due to RF links of the base station. For macrocell and microcell base stations, empirical formulae can describe the relationship between the power delivered to the antenna relative to the consumed power of the base station [13]. For macrocell stations the power consumption is almost independent of the input load (traffic) whereas for microcells, power consumption is highly dependent on the input load.

Making a network to operate in a green manner is a complex task. Sometimes, optimizing energy consumption in one part of the network can increase power consumption and degrade the performance of another part of the network. In general, total network optimization is better than the sum of optimizations of individual parts. A network to work in an energy efficient way is not only a matter of environmental protection through signing of memorandums but also a crucial factor for the deployment of future networks to off grid areas that rely on Renewable Energy Sources (RES) or personal and sensor networks that rely on battery power supply. Minimizing power consumption has also a great effect on the cost of operation of a network and this makes it more affordable to the user. Network energy efficiency can be considered as a very complex task since there is no clear solution to the problem. The sectors of the network that require the greatest attention are the electronic equipments of both end user and the access network, thermal removal processes, efficient network planning and base station design.

                                                                                               Compiled and written by: Samwel Kariuki