Renewable Energy for Powering Telecommunication Sub-stations
Executive Summary
The global objective is to lessen energy use and carbon dioxide emissions. The EU alone has purposed to reduce energy consumption by approximately 20% by 2020. This includes a reduction of energy in telecommunication sector. Telecommunication systems represent a key aspect of information communication and technology (ICT) that experience a remarkable development. Capacity as well as delivery of multifarious synchronized services is primary concern that lead to high trends energy use. In the competitive telecommunication industry, providers are moving to rising markets for their subsequently phase expansion that increases subscribers and the necessary equipment. This contributes to the installation of equipment to regions where renewable energy is required and efficient energy networks are significant. Telecommunication systems consume a greater amount of energy accounting for about 4% of the total energy use globally. Assessment on the significance of energy consumption in telecommunication stations has widely been reported. A substantial reduction of carbon dioxide emission can be achieved through the use of innovative telecommunication solutions such as electronic taxation systems, video conferencing and electronic billing can trigger the use renewable energy. The objective is to set up telecommunication services that have the capacity to conserve energy, producing effective ratios of enough Watts per user and Gbps. Renewable energy has been initiated by various operators.
Table of Contents
2.1 Wireless network energy consumption. 4
2.3 Recent advancements in renewable energies. 7
2.4 Sources of renewable energy. 8
2.5 Energy saving in telecommunication stations. 9
2.6 Energetic consumption related to telecommunication station. 9
2.7 Energy use for UMTS and GSM technologies. 10
2.8 Lowering the costs of Solar PV.. 12
2.9 More Robust Off-grid Technology. 12
3.0 BTS Energy Savings Approaches. 12
3.4 Sophisticated climatic Management Air Conditioners. 13
3.5 DC Power Appliances ECI Mode. 14
3.6 Elevated Efficacy Rectifiers. 14
5.0 Telecommunications and renewable energy. 17
7.0 Telecommunications power systems and environmental monitoring. 21
1.0 Introduction
The major concerns emerging from the development of energy consumption and important ecological emergency because of green house gases make individuals to initiate new techniques as well as technologies for producing energy to meet the needs of the increasing electricity demand. Climate change being experienced worldwide is a result of increased carbon dioxide and green house gases in the air is regarded as a vital global emergency that calls immediate and effective measures (Boccaletti et,al. 2007). On the other hand, carbon dioxide emissions in the atmosphere are largely because of consumption of fossil fuels. Therefore, in future it is vital to reduce the consumption of fossil fuels. This can be accomplished through efficient energy consumption and large scale use of renewable energy. This is a reality in telecommunication systems that have witnessed a substantial growth in installations and the increase in energy use due to high interest in innovative techniques. For instance, the development of telecommunication industry in the recent past has contributed to a remarkable growth and demand for energy. Evidently, energy use in telecommunication sector in particular operator system differs from 1.5-9 TWh annually. In fact on wired network there are possibilities of increase number of subscribers whereas on wireless network the amount of networked high speed applications is also increasing. In 2009, telecommunication industry consumed approximately 1% of the global energy, this corresponds to 15 million American homes and carbon dioxide emissions of 29 million vehicles. Hence, decrease of energy use in telecommunication stations indicates one of the main factors of telecommunications, to enable significant use of fiscal resources to mobile communication services and recognize sustainable actions. This implies that efficient use of energy in telecommunication systems is an important contribution in the prevention of global warming, though with rapid increase in the cost of energy, it is considered a economic opportunity. As such clear and innovative techniques should be implemented to increase initiatives of energy consumptions. Telecommunication network is similar to an ecosystem; one cannot use any energy saving approaches without necessary considering the consequences of other system aspects. For instance, energy logic technique can be use in both wired and wireless networks. The technique is centered on a holistic technique of energy saving and presents a comprehensive framework of policies while looking at various consequences. This paper intends to discuss some of the available sources of renewable energy for powering telecommunications base-stations as opposed to carbon emitting disease generators (Boccaletti et,al. 2007).
2.0 Literature review
2.1 Wireless network energy consumption
Archetypal wireless system can be considered to entail various elements such as
- Mobile switching centre or MSC which endures that deals with switching as well as interface to fixed networks
- Radio base station or RBS that deal that deals with frequency within mobile terminals and networks
- Mobile terminals this is on the user section generally it is restricted to hand-held application.
There are approximately 90 percent of wireless system is a section of the users expense. The main components are the RBS since the quantity of base station is somewhat greater with relatively high power utilization. Conversely, the quantity of main network components are less, this a result of the average power consumption that is low. Last but not least, energy use in mobile terminals is extremely low due to nature of mobile. With all these premises strategies of reducing energy use in mobile network leading to minimization of cost as well as carbon dioxide emission include; reducing the amount of energy use in BTS and using renewable sources of energy. Subsequently, to minimize the energy use, the quantity of BTS can as well as reduced (Roy, 2008). In this event, system layout plays a crucial part in the execution of telecommunication stations through precise ability and least number of stations in most favorable regions. With a typical RBS would lead to 10.3 kW of energy to generate 120 W while to process incoming signals from users cellular network with an average efficiency of approximately 1.2 percent.
Figure 1: RBS Block Diagram
The figure below indicates energy distribution per given function in RBS. Typical of several station, Over 60 percent of energy is used by radio amplifiers, the DC system uses 11 percent while cooling device, air conditioning consumes about 25 percent. Radio devices and cooling are two main areas in which the highest power savings prospects resides.
Fig 2: Percent BTS Energy per function
In the construction of the power saving, it is rather pertinent to consider a cascade impact that represents in average a benefit of twenty eight times: for instance, saving one watt in the feeder codes saves 17.3 watts of modulation as well as amplification losses, 3.3 W of rectification losses as well as 7.1 watts of related condensing energy.
2.2 Renewable Energy
The government of United Kingdom supports the development as well as promotion of renewable energy through provision of funding in form of capital grants and Renewable obligation scheme (RO). Renewable obligations encourages energy suppliers to distribute about 10% of power from renewable energy
2.3 Recent advancements in renewable energies
Renewable energy has gone through various developmental phases over the last couple of years. Some of the solutions viewed as unfeasible may now necessitate a second look. In telecommunications company for instance, diesel powered generators are used at the expense carbon free clean energy alternatives especially in far-flung off-grid base stations, because they are cheaper and more dependable. An important section of these base stations will be deployed in far-flung regions with negligible access to the electrical network (Lubritto, 2010). Diesel also known as propane generators are mostly employed to drive off-grid telecommunications base stations irrespective of the high operation as well as maintenance expenses. In most cases, these generators are combined with renewable sources of energy such as Solar PV and wind although 100% renewable energy sources are scarce, because the lower operation as well as maintenance expenses are inadequate to offset the higher capital expenses and the threat of intermittence owing to the lack of solar or wind energy. However recent developments might alter this, especially for solar PV energy alternatives installed in sunny countries: lower PV costs, more robust off-grid expertise and the wider accessibility of Energy Service Companies (ESCOs).
2.4 Sources of renewable energy
To decrease cost and emission of carbon dioxide in telecommunication systems, renewable energy sources (such as wind, photovoltaic cells, among other) can be set up on the infrastructure or used on off-grid telecom networks. The use of renewable energy sources has been widely analyzed for regions with unreliable power supply or remote that hinders regular maintenance. The preference for source of energy primarily depends on energy use, typology and local conditions. Wind and solar energy can virtually provide free power. Solar energy is an old technology that can be utilized for low and medium regions. They also have low effect on the environment, low maintenance costs, reliable compared to diesel and long technical cycle of over twenty years. Additionally, solar energy installation can be compared to real requirements without exerting uncalled for capacity (Ikebe, et, al 2007). On the other and, wind turbine have the capacity to support a conventional telecommunication network without high effect on cost, with an average wind speed. In many instances, a hybrid technique that incorporates solar and wind energy is the most appropriate solution for independent telecommunication station. In this case, wind turbine and solar cells has to be properly described with respect to solar and wind availability. Fuels cells are more and more being regarded as a feasible source of power for telecommunication networks. Consequently, they can be installed in regions with diesel generators and partially substitute batteries in remote regions with extensive back-up condition (Boccaletti et,al. 2007). They not only increase energy efficiency, they as well develop system up-time and consistency.
2.5 Energy saving in telecommunication stations
In comprehending management of energy in telecommunication networks, it is significant to conduct a power assessment of BTS. With this goal it has been understood that assessments of telecommunication devices beginning with on-site auditing, carried out in conjunction with mobile networks that emphasize on diverse technologies, locations, typologies, and working loads. With partnership of different telecommunication providers, it is easy to recover information from many stations. However, all the assessments are conducted via a particular monitoring method (White Paper Ericsson 2007).To carry out a statistical analysis as well as correlation it is imperative to consider some aspects including; network typologies (such as room, outdoor and shelter), network technologies (DCS, GSM and UMTS) and region. Consequently functioning indicators have to be considered. They include; energy use (Wh), instantaneous energy (W), Internal and external temperature (°C). A database has been set up with all the necessary information associated with energy use, technologies, typologies, location and environmental indicators.
2.6 Energetic consumption related to telecommunication station
Considering that the paper aims at calculating relevant statistics to determine energy use can lead to efficiency. In addition, the paper shows energy use correlated to transmission function of the devices and energy use associated with cooling of telecommunication stations. To achieve this objective, statistical analysis were developed based on the R-foundation statistical software. Based on these analyses one can conclude that: On a yearly basis BTS consumption is about 35500kWh compatible with average use of ten families. Considering the there are 60,000 BTS the average annual energy use of all telecommunication networks in UK is 2.1TWh that corresponds to 0.6% of the national power use (Lubritto, 2010). With regard to ecological and economic impacts, the information is equivalent to 300MW /year power costs and 1.2 of carbon dioxide emitted in the atmosphere annually. Conducting analyses of the total energy use related to different telecom technologies, GSM power consumption is greater than UMTS- as expected due to different form of function of two technologies as indicated below
| Energy Consumption/technology | ||
| Technology | kWh/day | kWh/year |
| UMTS | 7,297 | 26,268 |
| GSM | 11,135 | 40,085 |
Table 1: Energy Consumption for UMTS and GSM technology
2.7 Energy use for UMTS and GSM technologies
To assess daily energy use and contributions as result of transmission, it is important to differentiate two diverse patterns; a constant energy use of approximately 800Wh at night and morning, and a fluctuating pattern, with average consumption of about 1100Wh during hot hours. This pattern is recognizable only if energy consumption is for transmission purpose and conditioning power (White Paper Ericsson 2007). Therefore, energy consumption can be divided into two components about two-thirds that is used daily and one-third consumed by conditioning systems.
Fig 3 Daily Energetic Consumption of a BTS
To substantiate the latter perception, it is imperative to demonstrate energy distribution in four days. For instance, the first day was the coldest with temperatures of 2.8 -9.5 °C: blue line, the second day was a typical one with minimum temperature of 7.0-17.6°C; violet, the third day was the hottest with varying temperatures of 15.5-37.3°C; green line; the fourth day was also hot with temperatures of 21.8-42.5°C; red line. Based on this fact, there is a variation in the energy distribution during coldest days (day one and two), where instant energy is supposedly as a result of transmission purposes and indicate a maximum linkages of defined energy values and distribution purposes during warm periods ( day three and four) that exhibit transmission and condition functions. A global pattern of energy use vs. temperature can be estimated separately based on telecommunication technology as well as typology (Leddy, 2008).
2.8 Lowering the costs of Solar PV
Solar photovoltaic was previously one of the most capital-intensive types of renewable energy. But things are different now, and PV has become as cheap as wind energy. This cost-effectiveness is due to low production costs as well as manufacturing overcapacity.
2.9 More Robust Off-grid Technology
Some of the existing PV as well as wind installations are grid-integrated. Implicitly, windless or cloudy days will not negatively affect energy generation because of the backup presented by electrical grids. This is completely a different story with off-grid base stations, hindering the use of standard remote PV as well as wind solutions. Mining and Military domain are coupled with analogous challenges, and have been researching on how to innovate more dynamic off-grid mechanisms. The micro-grid is a typical example, one that integrates the hardware and software hence enhancing optimized control of various energy sources, traditional and renewable alike (Leddy, 2008).
3.0 BTS Energy Savings Approaches
Previously myriad Energy Savings Approaches for wireless systems, employed both the radio machinery as well as the condensing and power apparatus have been proposed
3.1 Remote Radio Elements
Remote radio compounds comprises in enhancing the RF converters as well as power boosters from the base of the station to the apex of the tower next to the antenna and linking them through fiber codes. This approach presents the higher prospective energy savings: most radio fabricators now present this topology.
3.2Radio Standby Mode
The subsequent approach is rather easy to execute and mainly comprises of an application and basic hardware improvement. Popularly known as the ECO Mode or Power Saving Mode, this approach comprises of rotating radio broadcasters and antennas off when the call traffic comes down, particularly in the night. After executing the ECO Mode, power usage can come down by forty percent under low traffic (Lubritto, 2010). By and large, this approach will lower the utilization of the radio equipment between ten to twenty percent, in addition to its related power alteration as well condensing energy needs. By and large this boils down to cascaded savings in the chronology of six to seven percent.
3.3 Passive Cooling.
The next area of concern is the cooling. Such condensation, expects about 33% of the heat generated inside the RBS. It is also a boisterous repair intensive solution. Based on the geological position, other cooling methods such as free aeration, coerced fan cooling with water repellant filtering as well as heath exchangers will modify considerably the energy usage, and often yield a lower combined cost of ownership. It is approximated that passive condensation can present energy savings above ten percent.
3.4 Sophisticated climatic Management Air Conditioners
In the event that an air conditioner remains essential, one can control its usage working at high temperatures at favorable instances. By so doing, the energy usage is decreased for two reasons, one that the lofty set point implies that the unit will not be put on quite often and secondly that it will function rather proficiently owing to the extreme temperature at their air exchange resulting into a savings of between 3-4 percent without main accessibility effects.
3.5 DC Power Appliances ECI Mode
The last two methods connect to the DC power plant. Clearly, at this phase, energy has been reduced based on the previous measures and brought into play the radio ECO style to enhance the load in times of low traffic sessions. A sophisticated appliance management scheme can make sure that rectifiers will function proficiently under whatsoever conditions.
3.6 Elevated Efficacy Rectifiers
Previous approach is the use of higher proficiency rectifies. In the event that all approaches are considered, collective savings above 58% are probable (Roy, 2008). When it comes to the radio end, employing the Radio model and using the Radio ECO functionality will lower the energy usage by 40 percent. About the system side of it, condensation charges can be enhanced by taking advantage of the use of the air conditioner or presumably, by drifting to a somewhat passive methods. This is likely to lower the usage by an extra 3 percent and 11 percent respectively down by 54 percent. In the end, the last 4 percent of the decline will emanate from the Direct Current (DC) plant by executing power control to maintain the rectifiers at their peak proficiency echelon and by using elevated effective rectifiers (Ikebe, et, al 2007).
4.0 Energy saving
Beginning from the empirical reviews on the BTS power usage, it is important to study the probable interventions for enhancing and cutting down energy usage. The main idea is to personalize significant interventions for saving action on conditioning structures and on transmission usage. Concerning the saving of energy usage necessary for the fun brings about two probable intervention approaches; the first is anchored on intelligent algorithms for maximizing the dynamical control of the funs operations, secondly, one was anchored on the local condensation of the single electronic appliances, which precludes ventilating of the background where they are situated. Both assumptions are centered on the fact that inside the enclosure the thermo-dynamic precincts can assume value ranges larger than in regions mostly used by people (Ikebe, et, al 2007). As such, the use of intelligent ventilating systems and traditional cooling systems are necessary approaches for energy saving, based on the probability to eliminate useless conditioning actions of the environs and automatic parts. One can approximate that such interventions can attain an energy saving from 5 percent to 10 percent of the ventilation usage. For making good use of the usage emanating from the transmission operations, it is evident that an application engineering by Ericsson is significant when it comes to using BTS-GSM energy transmission in what is termed as the proficient way. Algorithms of this kind can associate the phone traffic of a BTS as well as the energy usage. During phases of low infrastructure traffic, the element automatically puts transceivers that are not operating in standalone mode surmounting the conventional approach of having radio equipment fully switched on, which lead to power wastage.
Based on the system traffic trend, the model algorithm parameter settings as well as on the shape of instruments, this novelty can save from 5 to 50 percent of energy with respect of BTS especially when the base station is functional, whereas still presenting the same services and quality to users. The research has been conducted with a two pronged strategy: The experiment on BTS so as to have direct hints concerning the achievability of the project, the real anomaly, and the actual savings. To attain this objective on the field, measurements were conducted in a functioning BTS at moments when the feature was active and also when it was not active (Farar, 2007).
Conversely, it is not achievable and virtually undependable to navigate all the BTS energy usage and to determine the power saved with various perimeters of the model algorithm. This is to say a simulation study has been executed. The best configurations warranting effective communications and appropriate savings have been evident. An assessment between field analysis and simulations has been noted, with a view to enhance the configurations employed in the BTS energy saving model. Configurations relevant in this type of evaluation include telephone traffic, BTS typology and arrangement, number of transmitters. Analysis of energetic usage and other ecological configuration have been recorded in suburban BTS situated in Angliana consisting of 3 GSM transmitting gadgets and 3 DCS transmitter.
Figure 4: BTS power use
The result from the above figure indicates energy use at the radio station for twenty one days; two were activated to energy saving function. In this case, Rack 0and 2 stand for energy use of DCS transmitter, while Rack 3 represents energy use for all GSM transmitters. Apparently, average energy use is lesser when energy saving function is activated; a decrease of over 10% of energy use is clear from subsequent period.
5.0 Telecommunications and renewable energy
To initiate renewable energy in telecommunication networks, it is vital to consider the utilization of renewable sources of power (such as wind, solar and photovoltaic) being integrated in telecommunication infrastructures. Assessment of current technological services in photovoltaic industry essential in generating power regarding operation conditions as well as structural aspects of radio telecom station (Lubritto et, al. 2008). Interventions can then be assessed based on the location with diverse monitoring conditions for any given provider, so as to plan and understand photovoltaic networks for basic telecommunication station.
Thus using photovoltaic systems in addition to other renewable sources of power for various typologies and devices not accessible by electricity has already been evaluated. In order to realize the approaches of using BTS infrastructure to get average or partial architectural incorporation, it is significant to set up photovoltaic plant. This has indicated that their energy productivity largely rely on geographical aspect, available surface to execute photovoltaic plant. On both shelter as well as infrastructure, photovoltaic plant leads to variation of PV modules from 16-20 m guaranteeing a generation of 2-2.5 kWp.
These installation based on the information presented has generated 1000 and 1200kWh; this means a yearly estimated generation of 2640 -2880 kWh. This kind of application leads to environmental protection to some degree because roughly 3 Ton of carbon dioxide is not emitted annually for every BTS. To conduct particular controls and compare energy conditions both pre and post photovoltaic channel an inspection station has been employed to assist in the evaluation of operational indicators such as energy consumption, internal and external temperatures and other ecological indicators. Particularly, it is essential to assess the chances of executing more photovoltaic technologies (like thin film and amorphous), and assess the technicalities and economic advantage for any given solution. A suitable and feasible solution- technical as well as economic perception- instead of using single or multi crystal panel- is the utilization of panels that have thin film and amorphous
Fig. 11. Photovoltaic system installed on the BTS infrastructure (Vodafone)
6.0 Environmental Concern
Burning of diesel to power hundreds of thousands of mobile telecom base stations poses detrimental effects to the environment. A single base station for instance, burns around 20,000 liters of diesel annually, and emits about 50 tons of carbon into the atmosphere. And yet no other practice is rather monetarily onerous for mobile service providers. Running a single diesel dependant base station is likely to cost $40,000 annually. For various providers in developing nations, energy is a big issue that represents approximately forty to fifty percent of the overall running costs, whereas the energy cost is enormous owing to the use of fossil fuel to power base stations. However, there are many ecologically friendly options for powering base stations that run on diesel, especially those located in sunny as well as windy territories. There are various organizations offering a power management service that includes the sun and the wind, with management systems and battery reservoirs for energy capture as well as storage (Knott, 2008).
By and large, no huge involvement is expected, as the situation will change naturally. The tumultuous market forces are now mounting enormous pressure on mobile service providers to control their operating costs, propelled by the data boom that puts a strain on the system and rivalry that is clutching call rates. At the same time, mobile service providers should not expect diesel costs to drop any time soon. However, renewable sources of energy have now become strategic alternatives. Various factors indicate that we’re on the verge of a major shift to green base stations. Airtel for example has a massive plan to roll out hundreds of thousands of highly sophisticated green power alternatives in Africa. This is a paradigm shift with positive effects to the brand by switching from rusty stations to clean renewable energy. Telecommunications Company’s do not want to be viewed as bad guys (Lubritto et, al. 2008). The use of clean carbon free base stations as an alternative approach would preclude millions of tones of CO2 from being emitted in the atmosphere. Many services provider would cut down on running costs by 20%, while leveraging on their capital to dominate the market while investing strategically to meet the needs of hundreds of millions of customers, majority of which live off-grid. Yet with these clients typically of the low average revenue per user (ARPU) type, the use of cost-effective green power alternatives to serve them and equally enable them profitable for the operator. Green powered base stations are equally healthy to the environment.
6.1 Telecommunications Efforts to Curb Global Warming
The primary cause of global warming is carbon dioxide emissions. It is arguably being released to the atmosphere at a very fast rate by methods such as natural activity like volcanic eruptions and people breathing. Other causes that contribute to carbon dioxide emissions are burning of fossil fuels such as coal, petroleum and gas, emissions from factories, cutting down of trees which absorb and store carbon and release oxygen. Telecommunication companies should desist for all these activities destroy the environment by emitting into the atmosphere excess carbon dioxide (Efraimsson, 2008). There are very many suggested ways to combat or reduce global warming “the most important action to stop global warming is reducing carbon dioxide emissions which come from burning coal, oil, gasoline and other fossil fuels in telecommunications sub-stations” (Oxlade 2006). To reduce the usage of fossil fuel in telecommunications companies, it is prudent to generate energy in other ways such as solar power, wind power, hydroelectric and tidal power. In fact “the energy that comes from the sun is 6,000 times greater than the energy actually used” (Oxlade 2006). However, he also suggested that one form of sustainable fuel to use in reduction of global warming is biomass fuel which comes from burning plants or plant oils. In this case, the carbon dioxide that the plants take as they grow is balanced to the one the fuels release when they burn. Moreover, there are methods that can be taken by individuals to reduce the global warming such as planting trees since they will absorb carbon dioxide and provide shade to the environment from the heat. People should reduce waste from the products which they buy for use by embracing reusable packages instead of disposable ones. They should also buy fresh foods instead of frozen ones which consume lots of energy in production and storage. It is however important note that individuals can curb global warming by revolving around efficient use of energy using methods such as defrosting fridges and freezers regularly and moving them away from heat sources, installing fluorescent light bulbs, covering pots while cooking in order to save cooking energy, using less hot bathing water, using clothesline instead of a dryer whenever possible, using the car efficiently and where possible car pool in order to save fuel and reduce emissions (Hjorth et, al.2008).
7.0 Telecommunications power systems and environmental monitoring
It is extremely vital to examine the connection between energy, ecological consequences, and telecommunication stations. Some of the key aspects to be emphasized include; BTS effects on landscape, pollution produced by BTS, environmental consequences as a result of noise, or green house emissions. With respect to environmental consequences, it is important to set up a BTS. The likelihood to utilize structures of BTS plant to achieve energy generation system from renewable sources could be the solution to meet such demands. Evidently, such difficulties are not witnessed, however it is imperative to initiate the correct principles so as to decrease effects of BTS on the ecology, while executing innovative power sources. Besides, the likelihood to minimize the quantity of green house gases emission from telecommunications is related to the distributed generation of renewable power. Actually, the utilization of renewable power specifically in grid-off environment can substantially minimize the effects on the environment due to the telecommunication station as well as the management of feeding generators. Using wind or even photovoltaic networks may hinder the execution of feeding networks that should be operated with fuel on a daily basis. In other words, this would lead to a considerable decrease of emissions in the air. Of great significance is the effect on the environment particularly, during the closure of the project, this is because substantial diffusion of power lines (low frequency electromagnetic) and radio, television, mobile station (high frequency electromagnetic). Technically, it is always essential to understand a region since this can remarkable transform based on magnitude transmitters, distributed energy and environmental features like nearby buildings and other obstructions that establish the reflection that is changeable with a given time frame. Based on this premises and emphasizing on the theorized energy saving approaches, assessing views on the reduction of electromagnetic produced by BTS (Borkar, et al. 2010). It is important to recognize that using an energy saving approach can provide a valid benefit to the lessening of emissions generated by BTS. In reality, putting off transmitters implies a void production of electromagnetic thus leading to a decrease in daily emission by telecoms.
Analysis Section
Bandwidth between base stations (BS) will be analyzed in the event that users are interconnected by several base stations, and this will determine a suitable scenario to enhance coordination between the stations to increase the efficiency. As indicated in the figure below, when BS1 and BS2 employ distinct carrier frequency during transmissions, user equipment is selected based on the received signal to the noise ratio from every BS to assess which station has quality signals. On the contrary, when the two stations use similar carrier frequency during transmission, user equipment can increase the strength of received signals through combining received signals from the two stations.
User equipment in base station
In wireless communication, channel fading is extremely crucial. In case signals transmitted via the channel it will experience several interfaces like multipath when the signal transmits through forests, terrains and buildings. Nevertheless, multipath will increase or even fade transmitted signals thus hindering receiver terminal to precisely access transmitted signal; it requires statistical analysis to demonstrate the strength of received channel. In wireless communication, channel model is obtained via analysis as well as simulation of channel reactions and adjusted by way of empirical assessments; several channel models have been proposed. In short, the strength of received signal at BS or user equipment can be evaluated based on the equation below:
P(dBm )=P
In this case, pt is the transmitted energy of BS/ user equipment (dBm)
Gt is the antenna gain of user equipment or BS (dBi)
Gr is the antenna gain of BS or user equipment (dBi)
PL is the channel loss in dB and contains a
value as indicated in the
P(dBm) = Pt+Gt+Gr-PL (1)
Where
Pt: Transmission of base station Energy/UE (dBm).
Gt: Transmitter gain of EU/base station (dBi).
Gr: Transmitter gain of base station/UE (dBi).
PL is the trail loss in dB with values as indicated in the equation below as proposed by 3GPP.
PL= 161.04- 7.1 log 10(W) + 7.5 log 10 (h) – 24.37-3.7 (h/hBS) 2)
Log 10(hBS) + (43.42-3.1 LOG 10(hBS)) (log 10 (d)-3)
+20 log 10(fc)-3.2(log10 (11.75hUE)) 2-4.97)
Where the indicators are:
d: Broadcast space between the base station as well as the UE,
10m < d <5000m,
h: Average Base station height, 5m <h<50m.
W: Street diameter, 5m <W <50m.
hBS: Sub-station mast height, 10m <hBS< 150m.
hUE: UE mast height, 1m<hUE<10m.
fe: carrier frequency (GHZ).
User environment case
When a user is based in different coverage of BS, as show in the figure below, three different communication environments can be identified.
Analysis of Communication Environment
Presumably users are evenly distributed in every given base station that is represented with red zone. Users’ coverage in different base station can be identified through various colors. Simulated station performance together with user region is kept similar as indicated below for with coordination scheme and without coordination scheme.
Analysis of Base Station Spectrum Utilization
With regard to bandwidth utilization, user environment distributions are considered with executed coordination scheme. Conversely, in the event that user environment
| Tests of Normality | ||||||
| Kolmogorov-Smirnova | Shapiro-Wilk | |||||
| Statistic | df | Sig. | Statistic | df | Sig. | |
| DL10WC | .385 | 3 | . | .750 | 3 | .000 |
| UL10WC | .385 | 3 | . | .750 | 3 | .000 |
| SRV10WC | .385 | 3 | . | .750 | 3 | .000 |
| DL30WC | .178 | 3 | . | .999 | 3 | .956 |
| UL30WC | .178 | 3 | . | .999 | 3 | .956 |
| SRV30WC | .353 | 3 | . | .824 | 3 | .172 |
| DL50WC | .302 | 3 | . | .910 | 3 | .417 |
| UL50WC | .302 | 3 | . | .910 | 3 | .417 |
| SRV50WC | .369 | 3 | . | .789 | 3 | .087 |
| UL80WC | .375 | 3 | . | .773 | 3 | .052 |
| DL80WC | .360 | 3 | . | .808 | 3 | .135 |
| SRV80WC | .378 | 3 | . | .767 | 3 | .037 |
| DL100WC | .382 | 3 | . | .757 | 3 | .015 |
| UL100WC | .315 | 3 | . | .891 | 3 | .358 |
| SRV100WC | .354 | 3 | . | .822 | 3 | .168 |
| DL10WOC | .356 | 3 | . | .818 | 3 | .157 |
| UL10WOC | .356 | 3 | . | .818 | 3 | .157 |
| SRV10WOC | .356 | 3 | . | .818 | 3 | .157 |
| DL30WOC | .385 | 3 | . | .750 | 3 | .000 |
| UL30WOC | .385 | 3 | . | .750 | 3 | .000 |
| SRV30WOC | .385 | 3 | . | .750 | 3 | .000 |
| DL50WOC | .292 | 3 | . | .923 | 3 | .463 |
| UL50WOC | .292 | 3 | . | .923 | 3 | .463 |
| SRV50WOC | .292 | 3 | . | .923 | 3 | .463 |
| DL80WOC | .196 | 3 | . | .996 | 3 | .878 |
| UL80WOC | .196 | 3 | . | .996 | 3 | .878 |
| SRV80WOC | .196 | 3 | . | .996 | 3 | .878 |
| DL100WOC | .385 | 3 | . | .750 | 3 | .000 |
| UL100WOC | .385 | 3 | . | .750 | 3 | .000 |
| SRV100WOC | .385 | 3 | . | .750 | 3 | .000 |
|
||||||
Based on the statistical representation above, some data in the extreme right column are both less than 5% and above 0.005, which indicates that data in partly evenly distributed and also unevenly distributed. Implicitly data shows both nonparametric and parametric data. This therefore suggests that there’s both some significant Lilliefors Correction difference when users are connected by was a coordinated scheme and without a coordinated scheme.
T-Test Analysis
| Paired Samples Statistics | |||||
| Mean | N | Std. Deviation | Std. Error Mean | ||
| Pair 1 | DL10WC | 5.00 | 3 | .173 | .100 |
| DL10WOC | 3.600 | 3 | 1.2166 | .7024 | |
| Paired Samples Correlations | ||||
| N | Correlation | Sig. | ||
| Pair 1 | DL10WC & DL10WOC | 3 | -.997 | .052 |
| Paired Samples Test | |||||||||
| Paired Differences | T | df | Sig. (2-tailed) | ||||||
| Mean | Std. Deviation | Std. Error Mean | 95% Confidence Interval of the Difference | ||||||
| Lower | Upper | ||||||||
| Pair 1 | DL10WC – DL10WOC | 1.4000 | 1.3892 | .8021 | -2.0511 | 4.8511 | 1.745 | 2 | .223 |
In this scenario, the Paired Difference of the Mean between the two variables is 1.4 which suggests that successfully connected service usage with coordination scheme was greater connected users without a coordination scheme by 1.4. Again, the statistics demonstrates that the Paired Difference of the Mean is not empirically significant given that the Pearson and probability value is greater than 5%.
Wilcoxon Analysis
| Ranks | ||||||
| N | Mean Rank | Sum of Ranks | ||||
| DL10WOC – DL10WC | Negative Ranks | 2a | 2.50 | 5.00 | ||
| Positive Ranks | 1b | 1.00 | 1.00 | |||
| Ties | 0c | |||||
| Total | 3 | |||||
|
||||||
| Test Statisticsb | ||||||
| DL10WOC – DL10WC | ||||||
| Z | -1.069a | |||||
| Asymp. Sig. (2-tailed) | .285 | |||||
|
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|
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Wilcoxon Analysis indicates 2 negative ranks and 1 positive rank that demonstrate the direction between two sub-stations namely with coordination scheme implemented and without a coordination scheme implemented. This analysis indicates that for all 2 users without a coordinated scheme implemented was greater than users with a coordinated scheme implemented. However, the data does not demonstrate any significant difference between the two sub-stations. In reality users experienced a significantly lower connection without coordinated scheme (M=3.6, N, 1.216) than those with a coordinated scheme (M=5. N. 0.173), z= -1.069 p=0.285
8.0 Recommendations
For far too long oil has been at the center of business as the only main source of fuel for autos, generators and this reliance has enslaved the entire world. However solutions have been introduced to substitute the dependence of diesel generators, although the usage of the same is not widely practiced. Some of the alternatives to clean energy include electric powered, hydrogen powered engines, Alcohol and so forth. They have evaluated and examined closely right from the time they were conceptualized and many are of great significance over oil yet not so much has been done in terms engaging in a massive exploration of the same. This has been the outcome of mainly large oil organizations and auto producers, which have the political support and would rather remain contented to make giant leaps and bounds. This contentment has continued to make the consumer rely on imported oil and constantly process oil to a near depletion of all oil field globally (Knott, 2008).
Reliable sources have projected oil to last for less than 50 years before the world witness the end of oil reserves as we all know it. Individuals have now come to the realization of this truth and would endeavor to make necessary changes but are not sure how to get involved. CNG or Compressed Natural Gas is the other form of gas that not been highlighted as well as other alternatives. CNG has various benefits and completely zero negatives that present it with perfect reasons as the fuel generation the mechanized world will depend on in the future.
Electric powered engine technology acquired rare reviews but then lost steam so fast. The idea behind powering engines with electricity sounded a master piece for a number of reasons. The alternative was rather cheap and entirely clean. The vehicles were also said to be the only machines that could be plugged into the solar system. Different people came up with this notion and felt as if they had come to the ultimate remedy of their energy demands, although regrettably various deterrents come up rapidly. Electric machines hardly generated enough horsepower making them be used for developing nothing less than compact vehicles. This viewpoint made a lot of people change their stances since electric cars could not be employed for powering huge trucks or even small ones. Nevertheless, people also discovered that charging such a battery to full capacity would require four hours to achieve it. Its ultimate undoing was that such vehicles were not able to ply for close to 100 miles without recharging.
All these explanations made individuals to loose interest rather quickly. Sooner than later the public had lost interest, excluding Japanese who abolished all future schemes for electric cars. Hydrogen powered cell the followed the electric invention. This technology powers engines by harnessing Hydrogen atoms to run an engine. The central advantage of these hydrogen powered engines is that they emit water instead of polluting the environment. The demerits of Hydrogen were rather enormous. To begin with Hydrogen powered cells were so weighty and huge and that made them unsuitable in most engines. Hydrogen powered batteries and machines have proved applicable at all times. Telecommunications companies can also make good use of hydrogen powered batteries and engines because they are cost effective.
Natural gas is simply the basic concept of gasoline; nevertheless natural gas is mixed with air in the engine’s tube to create the internal ignition. Telecommunication companies should adopt natural gas engines in running off-grid sub-stations. Honda Company has been at the fore front of this innovation. Telecommunication companies going this direction can refuel their engines by way of a phil. Benefits of the Natural Gas Vehicles encompass:
- NGV Engines are accessible for almost the same price of regular engines.
- Engines that run on natural gas are safer because their fuel containers are thicker and stronger
- Natural gas cost is 30% cheaper than gasoline.
- Natural gas prices are stable than the erratic gasoline that are impacted by many geopolitical effects.
- Natural gas lower carbon monoxide by ninety three percent
- Natural gas lowers nitrogen oxide discharge by thirty three percent.
The use of traditional fuel in powering telecommunications sub stations is the main cause of air pollution. The production of certain gases by the use of such fuels leads green house effect that is perilous to the ecosystem. Therefore, an alternative to reduce air pollution is to develop other alternatives of energy. The most common forms of alternative fuels used to power engines are electric fuel, natural gas, hydrogen as well as fuel cell. Each of these fuels has their own benefits and disadvantages. The best alternative fuel will be the one that is cost effective and controls air pollution. There are several forms of generators depending on the kind of fuel used in it such as electric engines, hydrogen powered vehicles, fuel batteries and natural gas powered cars.
An electric powered engine does not produce pollutants and even if they do, it is cheaper to control it. Nevertheless, the cost associated with it is rather very high. Since the engine is electric powered, the refuel time is high and refueling is not likely in the case of power interruption. By and large the engine has a lower performance than and diesel engines. Hydrogen is an abundant gas in the air. The use of this gas in vehicles does not produce any green house effect. Nonetheless it emits small’s amounts of Nitrogen oxide (Roy, 2008). So the use of hydrogen would be perilous to the environment and this is difficult to store in vehicles. Hydrogen also has curtailed refueling system. On the other hand fuel cell produces electricity by the chemical reaction between certain gases such as hydrogen, methane, oxygen and so forth. The use of fuel cells in the generators does not emit impurities and such engines are environmentally friendly.
10 Conclusion
This research has helped me to understand other forms of alternative energy. Natural gas formed the basis of this paper. But you cannot talk about natural gas and leave out other forms of energy such as bio fuel, nitrogen, clean coal, hybrid and so forth. Natural gas remains the best alternative fuel to power the auto industry of the 21st century. The fuel is rather cleaner and more efficient and cheap than any other form of gasoline. Currently, organization such as Ford and Honda are exploring on how Fuel Cell cars function in real family set-up.
11. References
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Borkar, A.Ghosh, R.K.Singh and N.Chourasia, (2010) Radar Cross Section Measurement Techniques
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Eugene F.Knott, (2008).John F.Shaeffer, Michael T.Tuley, Radar Cross Section, 2nd Edition
Hjorth P.; Lovehagen N. , Malmodin J. & Westergren K. (2008). Reducing CO2Emissions from Mobile Communications – BTS Power Savings and Tower Tube, Ericsson Review n. 1,
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Ikebe H. ; Yamashita N. & Nishii R. (2007). Green Energy for Telecommunication Proceedings of INTELEC, pp. 750-755, 978-1-4244-1628-8, Rome (Italy), September 2007,
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