Network ModernizationFour practical solutions for cost-effectively modernizing your network
Network modernization challenges 3
An overview of solutions 4
Simplifying the top of the tower 4
Choosing the right fiber connectivity 5
Solving PIM 7
The advantages of a pre-assembled approach 7
3IntroductionThe task of modernizing a network is becoming increasingly more complex. Every network must be updated to replace aging technology, but the modernization process is an evolving target. As consumers purchase newer, more advanced mobile devices, the demand to increase bandwidth only compounds that need.
To meet increasing capacity requirements all the way up to 4G, wireless service providers are upgrading from conventional sites to top-of-the-tower remote radio unit (RRU) sites. With the pressure to add capacity, improve performance and cut operating costsall while finding an affordable, reliable upgrade pathmore and more providers are turning to fiber-to-the-antenna (FTTA) connectivity. As technology continues to evolvepumping more data through towers using less spectrumradio frequency (RF) performance standards are becoming more stringent.
If you are tackling the formidable task of modernizing your network, a comprehensive, well-informed viewpoint is your most valuable asset.
Network modernization challengesAlthough the network modernization process has many moving components and layers of complexity, there are several major challenges broadly experienced by the majority of providers:
Multiple spectrum bands and technologiesProtecting your current systemDeploying RRUs at the top of the towerEnsuring future readinessTime to market
4An overview of solutionsThere are many paths to network modernization, but providers must choose solutions that cost-effectively address their unique capacity needs and establish a foundation for addressing future technology evolutions. In this white paper, well focus on four practical solutions for modernizing both existing and new towers:
Simplifying the top of the tower with multiport antennasChoosing the right fiber connectivityEffectively addressing passive intermodulation (PIM)Pre-assembled and factory-installed deployments
The key objectives of a successful migration What is the best network modernization strategy for you? What are the best outcomes from any combination of approaches? To start, your solution should:
Minimize weight and wind load on strained towersAchieve the performance required to justify the investmentDecrease capital and operational expenses (CapEx and OpEx)Reduce the risk of installation errorsBe easy to upgrade and maintainBe repeatable and scalable
Simplifying the top of the towerWhen you focus on the critical assets and technology at the top of the tower, the path to network modernization can be challenging. One of the most difficult challenges is predicting future architecture. This is, arguably, the most complicated variable, often hiding costs for installs and maintenance, and often increasing the chances for error. The physical challenges of wind load and tower safety with added weight are also major concerns. Equipment may not be flexible enough to support current and future applications and services.
These issues and uncertainties add risk to the implementation process. As a result, providers are placing a premium on flexible solutions.
The antenna approach The top of the tower is especially challenging for new antennas. Crowded tower tops not only increase leasing costs, but often lead to installation headaches that drain resources. Antennas in close physical proximity to each other can distort patterns and impact signal performance. Service is also susceptible to interference between bands.
The use of multiple antennas also makes a wireless system vulnerable to failure. Each additional antenna or associated piece of equipment adds another layer of complexity and, with it, an opportunity for disruptive and costly equipment failure. Simply put, the more individual components added to the top of the tower, the more susceptible you make your network to downtime. Of course, recurring disruptions in service or performance issues can significantly impact a providers image, as well as the likelihood of reduced revenues from dropped subscribers who want fast and dependable service. Faced with loaded towers, interference issues and the threat of downward-trending revenue, wireless service providers want solutions that can safely and easily blend technologies, simplify tower architecture and perform reliably.
5Multiport antennas are ideal for simplifying and facilitating several bands and technologies. Multiple ports add the capability to support a variety of technologies in a single panel. Instead of numerous dedicated technologies apportioned between an array of antennas, providers gain a more versatile network structure capable of supporting multiple technologies and operator sharing.
From a structural perspective, multiport antennas can help reduce tower load. From a financial perspective, this approach also reduces CapEx.
The ultra-wideband option Wireless service providers are looking for ways to roll out new services that support the latest wireless device capabilities while continuing to provide services for older technologies. Uncertainty about future frequencies makes this challenge more complex. Along with this uncertainty is the practical matter of tower space: its often very difficult to find a viable spot for installing new equipment.
Ultra-wideband technology is an ideal solution for providers facing these issues. This technology provides a clear path to the future with multiport antennas, dual-band tower-mounted amplifiers (TMAs) and combining solutions that allow for sharing of antennas and feeders. Ultra-wideband solutions provide flexibility for multiple services operating from one antenna. This capability makes it much easier to overlay LTE onto 2G and 3G networks that are using GSM and UMTS bands. In areas where LTE in lower bands may need to be deployed in the future, this technology allows for a solid investment that reaps immediate benefits while significantly reducing costs for future antenna upgrades.
For example, one base station antenna can be used in place of six to provide services for GSM, CDMA, W-CDMA and LTE standards in 698960 MHz and 17102690 MHz bands. Many older antennas were deployed when PIM wasnt a concern, which means the equipment is not meeting todays PIM specification requirements for fast data rates and throughput. Older antennas can be replaced with new ultra-wideband models to support old and new services in virtually any frequency used within 698960 and 17102690 MHz bands. This solution saves tower space and offers the flexibility needed for future frequency wins.
At its core, ultra-wideband technology allows wireless service providers to implement new frequencies without adding more antenna faces. Its ideal for complex networks that feature a variety of technologies and physical layers. Key benefits include:
Increased speed to market and a cleaner, more visually attractive siteThe ability to support all major air-interface standards in almost any frequency rangeA reduced number of network antennas for lower tower leasing costs Greater performance in capacity-sensitive, data-driven environments
Choosing the right fiber connectivityAs newer RRU technology replaces conventional base transceiver station (BTS) units on the cell tower, more advanced optical fiber is replacing coaxial cable as the top choice for todays antenna applications, especially in outfitting and retrofitting hardware for FTTA applications.
In a typical FTTA configuration, baseband units (BBUs) communicate with RRUs via Internet Protocol (IP) signaling over fiber-optic cable. A short-length coaxial cable jumper is used only for RF transmission between the RRU and the antennaan approach much different than a conventional radio transceiver connected to antennas via one long coaxial cable.
UltraBandTM Antennas give you global performance in one package.
698960 MHz + 17102690 MHz
6This configuration offers several advantages. First, it eliminates the need for long, heavy coaxial cables. Second, it reduces weight load. Third, it minimizes RF losses. Finally, BBU cooling needs are greatly reduced; less air conditioning equipment means less space and power requirements.
There are two basic ways to approach tower connections: a single hybrid cable containing both fiber and power, or separate power and fiber cables run in parallel (Figure 1). A hybrid configuration combines power and fiber conductors in a single, high-performance cable for greater efficiency, capacity and savings. Hybrid cabling has many other practical benefits, including lower install costs, quicker deployments, greater durability, easier upgrade paths and redundancy.
7A hybrid system should be robust and flexible enough to withstand the test of time and accommodate future changes. Select a cable with fiber counts that provide double or triple redundancy, along with power conductor counts and sizes that support your anticipated RRU quantity and future power requirements. The next consideration is choosing the breakout system that best facilitates connectivity with the RRU. Traditional junction boxesor a new streamlined method using pre-connectorized canisters integrated directly into the trunk cableare two popular breakout methods. The advanced canister option eliminates the need for a junction box and allows a provider to use a single, universal hybrid fiber trunk cable that mates to RRU specific cable tails. These tails are configured at one end to match the specific fiber and power inputs of the different RRU brands and models in the industry and plug into the canister at the other.
When changes are made at the tower top, only a simple change of cable tails is required. Expansion is also accomplished in similar fashion. Redundant power and fiber elements from the trunk are simply connected through the pre-connectorized canister or junction box with tails and run to the new RRU.
Solving PIM When assessing network modernization options, every wireless service provider must address the pervasive and growing challenge of PIM. PIM is the result of two or more wireless signals mixing together to create undesired frequencies that cause interference or degrade the transmission of signals. With todays newer technologies, PIM can pose a significant threat to network quality.
When resolving PIM issues, providers should consider two major factors: RF cable assemblies and challenges at the top of the tower. The integrity and quality of your RF cable assembly technology is a crucial factor in minimizing PIM. Many tower components can contribute to PIM, especially as they age, becoming more susceptible to corrosion. Its important to choose components that are pre-tested and PIM certified. We will explore PIM in greater detail in a subsequent white paper as part of our Network Modernization series.
The advantages of a pre-assembled approach Beyond addressing PIM, providers must constantly replace aging technology. Advances in mobile devices and the race to increase bandwidth make it an ongoing necessity to update existing towers and build new ones. Todays extremely complex tower tops present a significant challenge in this area. A pre-assembled sector solution can help overcome it by applying cost-savings, consistency and performance benefits.
8www.commscope.comVisit our website or contact your local CommScope representative for more information.
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All trademarks identified by or are registered trademarks or trademarks, respectively, of CommScope, Inc. This document is for planning purposes only and is not intended to modify or supplement any specifications or warranties relating to CommScope products or services.
CommScope is an innovator in this area, offering Andrew SiteRise, the worlds first pre-assembled tower tops for RRU site architectures. The pre-assembled sector solution is radio access network (RAN) vendor-neutral. It supports up to four RRUs per sector and virtually all radio frequency bands, from 700 MHz to 2690 MHz. Since only one assembly unit is mounted to the tower per sector, SiteRise decreases OpEx by reducing long-term leasing, maintenance and labor costs.
ConclusionEvery provider should consider the complexity and cost of network modernization. It raises many questions:
What is the most cost-effective path to FTTA?What is the right approach to connections?What are the pros and cons of fiber versus hybrid?How can we minimize the PIM issue? How can you simplify the top of the tower?How can you prepare for future frequency bands?
A comprehensive, holistic network modernization strategy tailored to your specific requirements will help you maximize performance and durability while paving the way for future upgrades. Fortunately, there are viable, proven solutions that can help you modernize your networkaffordably and efficiently.
Interested in more information about network modernization? This is the first in a new series of Network Modernization white papers published by CommScope. Subsequent papers will delve into greater detail on many of the technical aspects, logistics and costs of the modernization process.