Wireless LTE Deployment: How It is Changing Cell Site Energy and Infrastructure Design


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Mobile broadband is becoming part of the daily life of an increasing number
of individuals, especially as the internet generation has become accustomed
to immediate broadband access at home, in the office and on the road.

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Wireless LTE Deployment: How It is Changing Cell Site Energy and Infrastructure Design

  1. 1. A White Paper from the Experts in Business-Critical Continuity™Wireless LTE Deployment:How It is Changing Cell Site Energy and Infrastructure Designby Paul Misar, Director, Product Management, Energy Systems
  2. 2. Summary Mobile broadband is becoming part of the daily life of an increasing number of individuals, especially as the internet generation has become accustomed to immediate broadband access at home, in the office and on the road. Introduction Today, business-minded persons use their mobile devices for voice, email and internet connections, focusing on a higher level of business productivity. In fact, data applications, such as video, presentations and multimedia applications, have surpassed voice as the primary wireless transmission. As this new business society relies more and more on this mobile connectivity, greater demands have been placed on the wireless infrastructure to support these transactions. In conjunction, handset manufacturers are releasing a greater number of smart devices to the market. These rely heavily on a myriad of data-intensive applications well beyond the standard voice application of just five years past. The result is an explosive amount of data moving through the wireless infrastructure, with certainly more to come.2
  3. 3. 100 90 80 70 60Speed (Mbps) 50 40 30 20 10 0 GSM/Edge Early UMTS HSPA LTE (enhanced UMTS) Figure 1. Mobile Network Technology As smart technology devices gain applications such as mobile video place quickly is becoming the choice of existing increased acceptance in the wireless even greater demands on the current mobile service providers globally. Giving marketplace, the overall infrastructure third-generation system. existing service suppliers the advantage, has been forced to evolve and meet the LTE can be built on the existing infra- To meet the increasing demand of the demand of the new data-centric con- structure platform of previous mobile consumer for faster data connections, sumer. The current broadband system radio systems. Further investigation of the industry has responded with two has become overburdened in its ability to this implementation can determine new wireless platforms—WiMAX and process the sheer amount of data that is how LTE affects the overall mobile Long Term Evolution (LTE)—as the transmitted by the end users, especially network infrastructure today [Figure 1]. next-generation wireless platform in larger urban areas. This evolution has technologies. WiMAX primarily has been quickly outpaced the use of standard deployed in areas where little or no wire- voice transmissions in the mobile arena less broadband connectivity has been both domestically and globally. Newer previously served or where a new player has emerged into a specific market. LTE 3
  4. 4. LTE has led service providers to rethink A balance must be considered between initialtheir current deployment strategies inorder to provide the highest data speed infrastructure costs, debt and possible loss ofthroughout their networks. Highest data revenue because of competitive pressure.speeds are attained when the antennasare closest to the user or consumer.Therefore, one of the main strategies It is noteworthy to mention that as the While the cost of investment is initiallyhas been to move to a more “mesh” or convergence of data, voice and video high, several factors drive providers“nodal” infrastructure throughout the networks moves forward, the wireless, to quick implementation. A balancenetwork to achieve this end goal. This wireline and cable networks are also must be considered between initialdeployment strategy involves a greater converging. These platforms cannot infrastructure costs, debt and possiblenumber of sites, with lower power exist without each other, as greater data loss of revenue because of competitiverequirements through the network and use and greater LTE efficiencies require pressure. If such pressure exists, theat each broadcast site. In many cases, a more data to be processed by the wired move to LTE will be forced sooner; ifsingle cell site services multiple antenna network. LTE is pushing the fusion of the there is limited competition, the choicesites, drastically reducing the overall networks, and within the next three to to wait and implement is possible.infrastructure build. This topology five years there will emerge a completely Waiting for implementation allows forpromises to increase the reliability of the different topology from that which eventual price reductions and systemnetwork and decrease the overall power exists today. optimization. Some providers mayrequirement at each site, and throughout However, service providers must face choose to sit on the sidelines, allowingthe network as a whole. The approach the cost of entry when considering an those with deep pockets to vet theis also attractive to many service provid- LTE upgrade, which may be beyond process and drive prices down.ers that are focused on reducing the their means. Yet, basing the decisionoverall power budget spent throughout to upgrade purely on infrastructure The Mobile Drive Toward Datatheir network. costs may be a flawed approach to Of the approximately 3.5 billion mobileThe promise of LTE’s smaller powered network enhancement. subscribers today, worldwide, 3G (thirdsites imposes an overall shift in the generation wireless networks) accounts The “big three” U.S. providers arenetwork topology as well as the system for 350 million with an additional capable of launching LTE technologyrequirements at each cellular site. Cell 35 million added every quarter. It is through self-funding. Small providerssites will become smaller as higher den- estimated that by the year 2015, 3G have access to low interest loans throughsity electronics require less power and a subscribers will surpass 2G (second gen- the U.S.-based “Broadband Initiative” inmore remote base transceiver system eration wireless networks) subscribers. order to provide high speed internet(BTS) solution, as well as nodal approach, This move took five years less than it services to communities that haveis taken. These two changes drastically took 2G to surpass traditional analog limited or no coverage today. Mid-sized,reduce the amount of DC power wireless networks.1 second and third tier regional providersrequired at each site, reduce the who do not have high cash flow and LTE is forecasted to reach 32.6 millionoverall cooling requirements, and profitability or access to government subscribers globally by 2013, withultimately reduce the total site footprint. funding will most likely struggle with Asia-Pacific leading the charge, followedAll of these factors combined produce the decision to move to LTE. by Western Europe with 9.9 million sub-long-term savings to service providers scribers, North America with 6.7 millionin both infrastructure spend and annual subscribers and Eastern Europe withoperational cost. 1.5 million subscribers.24
  5. 5. What are the drivers for the implemen- 3.5tation of a new wireless platform? It Broadband Subscriptions (billions) 3.0could easily be argued that many of theexisting service providers have struggled 2.5to successfully deploy the current 3G 2.0infrastructure in the network today. 1.5With limited additional spectrum avail-ability and high infrastructure costs, it 1.0may appear on the surface that a viable 0.5business model does not exist for imple-mentation of a new network overlay. 0.0 2007 2008 2009 2010 2011 2012 2013 2014But today’s service providers are drivenby two specific market trends. Smart Mobile Broadband Fixed Broadbandmobile devices and their subsequent Figure 2. Ericsson White Paper – An Introduction”. June 2009. 2009. Ericsson White Paper, “LTE “LTE-An Introduction”. Juneapplication-driven platforms have placedan increasing data-centric model onmobile providers in recent years. Also,the current generation of users, who 15were initially accustomed to voice only 13 Relative Network Loadand M2M (message to message) applica- Packet Data 11tions are slowly being replaced with anew generation of smart users who insist 9on mobile social networking and 7YouTube-style video applications. As a 5result, the trend over the past few years 3 Voicealone has evolved toward a data-centricwireless network. 1 Jan 07 May 07 Sep 07 Jan 08 May 08 Sep 08 Jan 09Broadband subscriptions are expected Figure 3. Ericsson White Paper – An Introduction”. June 2009. 2009. “LTE-An Introduction”. June Ericsson White Paper, “LTEto reach 3.4 billion by 2014, with about80 percent of consumers being mobilebroadband users. Figure 2 details the data within a typical mobile broadband manufacturers in the driver’s seat, pro-explosive growth in mobile broadband network has increased dramatically viding a suite of data-intensive productsover the past few years. It also projects over typical voice transactions from driven by third-party applications. Thisthe number of fixed broadband users 2007 through 2009. This is attributed trend has contributed to the extensivewill remain nearly static over the same directly to the increase in use of smart mobile broadband use over standardtimeframe. Fixed broadband is defined mobile devices. wired broadband throughout the world,as DSL or cable modem, or, basically, and will continue to move the trend Initially, device providers were drivena wired connection. This information forward. This trend is also evident in by the mobile network’s ability to carryalone seems to be a major driver for regions worldwide that have very limited data. But with the evolution of third-today’s mobile service providers to access to traditional wired networks. generation mobile networks in recentadopt greater broadband coverage In many developing areas around the years, the consumer’s quest for fasterwithin their respective networks. globe, it is both easier and cheaper and more data-intensive devices andAdditionally, Figure 3 shows how to deploy a mobile network than a applications have placed smart device traditional network. 5
  6. 6. The Evolution of Wireless BackhaulIn response, mobile providers have Since LTE brings dramatic increases in connection into the network. This couldbeen forced to develop a long-term data-carrying capability in the network, consist of second generation voice onlysolution to meet increasing and the ability to process data will become a networks, as well as third generation/LTEevolving network capabilities. Service key distinction of each carrier. Traditional radio solutions.providers demanded unified network voice service will be converted to data,enhancements such as, more efficient increasing the load on the backhaul. Reliability:spectrum usage capable of reusing the Data, not voice, will ultimately become The backhaul traditionally is the weakestexisting network, increased speed and the revenue stream for the service link in the network and reliability mustcapacity at the edge of each cell and providers. This leads to four specific be increased dramatically as demandseamless global access. To meet ever- areas that must be considered. grows. To ensure success, backhaulincreasing data speeds and the needs of spend will increase as providers work tothe service providers, the OEM commu- Cost: deliver more robust backhaul systems.nity developed the new LTE standard. Dramatic increases in data traffic In review, several possible future trendsLTE promises to provide: require additional bandwidth back into become apparent in the management of An all-IP network, flat architecture the system. Traditional copper-based T1 data from the LTE mobile network: systems become easily eclipsed in their Efficient spectrum usage, scalable Data will or already is the dominant ability to handle large data flows, unless from 1.4 to 20 MHz (one size fits all) player in mobile networks; voice is large numbers of T1 Lines (10+) are An open standard, capable of inter- secondary. installed at each site. The cost of leasing facing with existing 2G/3G devices these lines back to the local wired net- Providers that manage data securely Capability to re-use the existing work provider could exceed $10,000 and quickly though their networks radio infrastructure (U.S.) per month. Transition to an will become the dominant players in High network security Ethernet-based fiber backhaul system each respective market, especially or high speed microwave backhaul for secure and reliable business Initial capacities of 100 Mbps becomes the clear choice for LTE in transactions. data upstream and 300 Mbps order to better manage data traffic Voice-only wireless service providers data downstream efficiently through the network in a will become the low end providers,With data-centric standards such as LTE, more cost effective manner. Rather than while those who manage thethe need for a more robust backhaul in rely on the local exchange for backhaul backhaul/transport systems willthe network must be considered. But the services, the wireless provider is now become the dominant force in thebackhaul of data to the wired network capable of maintaining the link back future mobile broadband. In fact,has its own set of challenges with the to the wired network, further increasing voice-only services may become aoverlay of LTE into the network. Greater reliability and reducing overall “free” service as part of bundleddata use and greater efficiencies prom- infrastructure costs. data packages.ised by LTE means that more data isprocessed back to the wired network. Convergence: Overall, ownership of the networks willIn the past, wireless networks relied The backhaul environment must be slowly evolve to one or two dominantheavily on the use of T1 backhaul at capable of interfacing seamlessly with network management providers that selleach wireless site. These were primarily both 2G/3G applications as well as LTE. and manage the broadband networks.copper-based systems that were very The front end of the business will evolvelimited and many times unreliable in Flexibility: into service providers that sell mobile,their ability to process data back to the The backhaul must be flexible enough advanced data products and have few ornetwork. In many cases, the T1 lines to reliably handle all types of existing no ties back into the managed data net-became the weakest link at the cellular and future infrastructures at the point of work. In the near future, this will cause asite due to poor reliability of the points. major revolution in the market as well as affect the overall site infrastructure.6
  7. 7. The Effect of LTE on the Wireless InfrastructureHow will these business models affect that can do more in a smaller, more Because data speeds decrease dramati-the overall infrastructure of the wireless cost-effective manner at “greenfield” cally as distance increases from thenetwork from an outside plant, DC sites, and utilizing the preexisting infra- antenna, the wireless network mustpower and services standpoint? As LTE structure at established sites. Some move closer to the consumer to attainevolves, all of the service providers will deployments that make use of more the speeds capable of providing thesemove toward a data-only network, carry- efficient scenarios are: data intensive services, especially as weing voice-over in the Internet in packet DAS or Distributed migrate toward the wireless ‘smart’data form – or standard VoIP format. Antenna Systems home. One method involves providingThis will force providers to charge a flat neighborhood DAS-style networks Remote Node B Solutionsfee to compete initially with fixed-wire [Figure 4]. DAS places multiple antennas Although the traditional wireless site willsuppliers on the data side. In order to do throughout the neighborhood to pro- not disappear, LTE will force providers toso, great pressure will be placed on the vide extensive coverage fed by a main move toward less traditional methods inoverall cost model of the infrastructure DAS “hotel” located in the network. order to extend the network closer toside. As the unified standard of LTE is the subscriber. The mobile user may not The main DAS hotel contains incom-adopted, a more unified approach to necessarily be physically moving, but is ing utility power, DC rectification,cellular deployments may occur, with a never in the same static place continu- radio systems, fiber splitter andstrong focus on doing more with less ously. Also, as LTE evolves, “smart fiber management, node splittersfrom an outside plant, DC power and technology” homes will become more electronics and battery backup.site layout. prevalent, using wireless to provide This main hotel can be housed in aAll in all, cost pressure will be imposed energy conservation through smart walk-in enclosure or a series of smallon the infrastructure suppliers in the metering, full HD wireless television, outside plant cabinets. Site style willcoming years at a much greater level phone service and high speed internet depend on availability and cost ofthan has been seen in the past. This will capable of exceeding the fastest wired property, as well as the need forbe in the form of providing solutions DSL currently available. growth. Sites that do not require large growth potential are best served with several outside plant cabinets. Growth areas are best One facility can house Typical BTS Hub will Small antennas placed served with walk-in enclosures that equipment from be located in an on existing utility poles, existing office building can easily add radios, carriers, DC multiple wireless streetlights and/or service providers or other facility traffic signals power and battery backup. The traditional sector antennas are split up, or duplicated among sev- eral antennas fed via fiber, generally strung along existing utility wires. Legend Antenna Utility Poles Building At each antenna node, power is fed Node Fiber Cable Homes by the existing utility company via a BTS Hub point of demarcation.© 2008 ExteNet Systems, Inc. Site nodal electronics are poweredFigure 4. DAS Network by approximately 200 watts of DC power at the site and usually do not have any DC battery backup. 7
  8. 8. Remote Radio Unit Antenna (120W) RF conversion Antenna & Power Application (1170W) Feeder (120W) DC Power DC Power Optical RF conversion Fiber AC System & Power AC System (2190W) m Signal Processing Amplifi catio m Signal Processing Cooling & Control (4160W) Cooling & ControlPower with no Radio Base Station Radio Base StationFigure 5. Nodal Wireless SolutionDAS network sites, in general, are Existing providers will initially deploy and battery backup that has beencapable of three times the coverage of LTE within the current infrastructure, oversized to the current site powera traditional wireless site with the same especially if the radio frequencies are loads. This is not always the case,number of carriers. Main DAS hotel sites available. Based on scalability and but with the rollout of 3G, manydo not require large DC power plants interoperability of LTE, the most service providers oversized DCand large battery backup, as little or cost-effective solution is to add an LTE power plants and DC backup at theno amplification is needed to send the radio system at an existing cellular site mobile site, having been caughtsignal through the fiber network. Hotel utilizing the existing radio infrastructure. with limited DC growth potential insites can easily use less than half the This can be accomplished by: the past. In addition, many OEMcurrent DC power and battery backup. Deployment of the LTE radio at radio suppliers conservatively over-From an infrastructure standpoint, sites the site, either adding an outside stated the power draw at each site.require less AC power and less overall plant cabinet to an existing outdoor In reality, most sites only draw ainfrastructure footprint. site or indoor radio to an existing fraction of the DC power provided walk-in enclosure. at the site, leaving additional powerAlthough a nodal site with antennas for new LTE sites. This providesrequires DC power, AC demarcation and Deployment of RxAIT equipment considerable margin at each siteoutside plant cabinets, these compo- at the site, capable of combining for growth, allowing new LTE radionents pale in size and energy compared to existing WCDMA and LTE onto exist- systems to tap this reserve.an equal primary radio site [Figure 5]. In ing coax and site antenna systems. This saves considerable money The speeds required at existing sitesmany cases, the nodal side is connected and time at each site because new to maintain a “digital house” willto the utility grids with no DC back up. coax cables and antennas are not never be attained unless antennas areThis may evolve based on the critical deployed. In many cases, existing placed close to the subscribers. Thisnature of the data being transferred and frequencies are reused. will become an issue as more mobilethe types of businesses or individuals broadband is required by fixed homeserved by the network provider. Utilization of existing DC power and or business users. As the fixed mobile DC backup at the site. Overall, most mobile sites have existing DC power8
  9. 9. The Energy Factor Energy cost reductions in wireless A more recent development that allows DAS network sites, in networks are key to service providers. providers to dramatically reduce grid general, are capable of As infrastructure cost is pushed down- energy consumption at each site is the three times the coverage ward, so will the need to minimize the use of hybrid control systems that amount of energy consumed at each enable the deployment of renewable of a traditional wireless site. Current estimates show that energy sources. In addition to utilizing site with the same nearly one percent of global energy grid power, plus a DC generator or DC use is consumed by telecommunication batteries as standard backup, renew- number of carriers. networks. Many prime telecommunica- ables incorporate power from solar, tion providers are focused on reducing wind or fuel cells at each LTE site, reduc- the amount of energy used within the ing grid-generated power consumption. network as well as at each cell site. Hybrid site architectures have been used With more than four million cell sites extensively in China and more recently deployed globally, the impact of at sites throughout California. They energy savings is significant. provide a grid energy reduction ofrequirements grow at each cellular site, Optimization of each cellular site is key approximately 25 to 30 percent per site,so will the issues of moving the anten- to the reduction of energy absorbed by presenting the potential for significantnas closer to the broadband subscriber the mobile network. To date, the focus energy cost reduction when multipliedto optimize speeds at the network’s has been primarily on the amount of by the number of sites. U.S. sites canfringe. Although increasing penetration energy consumed by the radio system also realize a 30 percent federal energythrough signal amplification may be and the overall amplification of the tax benefit for utilizing renewablea viable solution, the cost of added signal at each site. Many greenfield energy sources, and several states offeramplification equipment and DC power deployments now utilize remote radio tax incentives as well. Renewable energyrequirements may be outweighed by heads, or Node B configurations, at the also gives providers an environmentalplacing a distributed node antenna primary cell site. These configurations advantage that reinforces their overallsystem closer to the subscriber. place the amplification and antenna at sustainability message.Ultimately, nodal sites may be the top of the tower, while leaving thethe solution to distribute signals In LTE networks, decreased energy radio, DC power and energy backup ateffectively through the network. consumption at each site allows for a the base. This configuration can cut the broader use of renewable and hybrid amount of DC energy and utility power energy sources. This creates the oppor- by as much as 50 percent at the site, tunity for the systems to be packaged directly affecting the amount of DC for rapid deployment, providing overall power, outside plant and AC distribution economy of scale and flexibility. at each site by a factor of one half. Payback, based on current electric Although these components are still rates, can be expected to be between required at each site, the amount three and five years. and size is drastically reduced due to the overall efficiency of the radio distribution. 9
  10. 10. Conclusions ReferencesFixed mobile broadband is growing at a Renewable energy located at LTE sites [1] Ericsson White Paper “LTE–rapid pace and will continue to overtake will provide an eco-friendly solution An Introduction”. June 2009.existing wired solutions as speed and with economies of scale through a [2] Ericsson White Paper “LTE–efficiencies increase dramatically. The packaged approach. Solar, wind and An Introduction”. June 2009.wireless industry believes that LTE is the fuel cells can not only reduce the reli-vehicle to provide this transition. This is ance on grid power by 25 to 30 percent,evident by the overall growth in the mar- but offer owners tax advantages andketplace for smart mobile devices and the opportunity to reinforce theirthe applications driving the amount of sustainability message as they reducedata, which has surpassed voice and their carbon footprint.will continue to grow exponentially. As The leaders in the wireless telecommuni-the use and evolution of smart devices cation infrastructure business will beincrease, so too will the need for faster providers who find unique ways tospeeds and a mobile network capable of enhance the robustness of the transportsupporting such data devices. Although network while maintaining costwireless networks are focused on mobile effective, energy efficient means.users today, it is a matter of time beforethis application is required at fixed busi-ness and fixed residential locations. Thiswill require broader-based distributedantenna solutions that focus on driving Solar, wind and fuel cells can not only reduce thethe price of each component further reliance on grid power by 25 to 30 percent, butdown to a commodity scale. What wasonce regarded as the centerpiece of the offer owners tax advantages and the opportunitycellular network will be viewed as a mar- to reinforce their sustainability message as theyginal component of the network; it willbe more cost-effective to discard than to reduce their carbon footprint.fix in the field. The days of high pricesand high technology are slowly fadingunder cost pressure within the market.What will set vendors apart is the abilityto provide cost effective, energy effi-cient, flexible market solutions to thecellular networks. As stated, the focuswill shift from cellular infrastructurecomponents to the transport orbackhaul portion of the business.10
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  12. 12. Emerson (NYSE: EMR), based in St. Louis, Missouri (USA), is a global leader in bringing technology and engineeringtogether to provide innovative solutions for customers in industrial, commercial, and consumer markets through itsnetwork power, process management, industrial automation, climate technologies, and tools and storage businesses.For more information, visit: Emerson.com.Emerson Network Power, a business of Emerson (NYSE:EMR), is the global leader in enabling Business-Critical Continuity™from grid to chip for telecommunication networks, data centers, health care and industrial facilities. Emerson NetworkPower provides innovative solutions and expertise in areas including AC and DC power, precision cooling, embeddedcomputing and power, integrated racks and enclosures, power switching and controls, infrastructure management, andconnectivity. All solutions are supported globally by local Emerson Network Power service technicians. For moreinformation on Emerson Network Power’s full suite of solutions specifically supporting the communications networkinfrastructure, including NetSpan™, NetReach™ and NetXtend™ outside plant enclosures and equipment, NetSure® DCpower systems, and NetPerform™ Optimization, Design & Deployment services, visit:EmersonNetworkPower.com/EnergySystems.Learn more about Emerson Network Power products and services at: EmersonNetworkPower.com.This publication is issued to provide outline information only which (unless agreed by Emerson Network Power Energy Systems, North America, Inc. in writing) may not beused, applied or reproduced for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. EmersonNetwork Power Energy Systems, North America, Inc. reserves the right to alter without notice the specification, design or conditions of supply of any product or service.Emerson®, Emerson Network Power™, Business-Critical Continuity™, NetSpan™, NetReach™, NetXtend™, NetSure® and NetPerform™ are trademarks of Emerson Electric Co.and/or one of its subsidiaries.Additionally, this white paper references the following company trademarks: Ericsson and ExteNet Systems. Names of companies are trademarks or registered trademarksof the respective companies. Any questions regarding usage of trademark names should be directed to the original manufacturer.Emerson Network PowerEnergy Systems, North America4350 Weaver Parkway, Warrenville, IL 60555Toll Free: 800-800-1280 (USA and Canada)Telephone: 440-246-6999 Fax: 440-246-4876Web: EmersonNetworkPower.com/EnergySystemsEmerson Network Power.The global leader in enabling Business-Critical Continuity™. EmersonNetworkPower.com AC Power Embedded Computing Outside Plant Racks & Integrated Cabinets Connectivity Embedded Power Power Switching & Controls Services DC Power Infrastructure Management & Monitoring Precision Cooling Surge Protection© 2011 Emerson Network Power Energy Systems, North America, Inc. All rights reserved.Code: 137W-LTE / 0111