4G LTE as a WAN Solution for Enterprise

September 2015 | ©2015 Cradlepoint, Inc. All Rights Reserved.

4G LTE as a WAN Solution for Enterprise

Commercial Wireless Networks RAN Capacity and Business

Considerations

Wireless Technology White Paper

By Chris S. Neisinger, P.E. (bio on last page)

September 2015 Page 2 CSN Consulting ©2015 Cradlepoint, Inc. All Rights Reserved.

Contents Executive Summary ..................................................................................................................... 3 Introduction ................................................................................................................................... 4 RAN Solutions Support Capacity and Efficiency .................................................................. 7

Spectrum Augmentation ..................................................................................................................... 9 Scheduler Improvements .................................................................................................................... 9 Interference Cancelation ...................................................................................................................... 9 Interference Reduction through Design (SON) ............................................................................. 10 Co-‐‑Ordinated Multi-‐‑Point (CoMP) .................................................................................................. 10 C-‐‑RAN/Cloud RAN ........................................................................................................................... 10 Carrier Aggregation ........................................................................................................................... 10 Small Cell for Efficiency vs Coverage ............................................................................................. 10 Application Aware Scheduling ........................................................................................................ 11 Edge Processing and Distributed Architectures ............................................................................ 11 Other Technology Improvements .................................................................................................... 12

The Business Landscape ........................................................................................................... 13 Applications ................................................................................................................................ 15 Conclusions ................................................................................................................................. 17


Section 1 Executive Summary

The advent of 4G LTE has been transformational in the wireless industry. Service providers like Verizon, O2, Vodafone, and Telefonica (and may others worldwide) have focused on data performance, quality and resiliency; and now LTE wireless networks have become as reliable as or arguably even more reliable than traditional fixed networks. LTE has a fundamentally strong ecosystem. There is ongoing development that is delivering capacity solutions to meet the ever-‐‑growing demand. 4G LTE is a viable transport technology to support many enterprise use cases as a primary WAN source. The majority of enterprise use cases at distributed/branch/remote locations can benefit from the simple, flexible and cost effective LTE last mile solution, even in the face of ever-‐‑escalating data usage. This paper looks at the network service providers’ capacity enhancement techniques, the business landscape and potential applications of 4G LTE as a primary WAN solution. Like any wireless solution, LTE does not meet all needs in all places. However, if the enterprise use case can be supported and there is quality signal at the location, adopting an LTE backhaul solution can bring agility, reliability and cost savings to your business.


Section 2

Introduction There is a clear and sustainable demand trend for wireless data. The 2015 wireless industry predicts 57% compound annualized growth through the end of the decade. Much of the basis for this growth is due to the proliferation of smartphones and the introduction of high capacity LTE networks.

Source: Cisco VNI Mobile, 2015 4G LTE was launched in the U.S. on single band 2x10 MHz spectrum blocks. This provided higher capacity per spectrum resource than the legacy 3G networks, but the capacity was quickly taken up by user demand. The industry anticipated this demand, and multiple frequency bands were added/converted to 4G. The LTE radio technology is the most advanced wide area wireless data solution in the world. Long Term Evolution is not an interim technology. 4G LTE can and will continue to evolve to support the ever increasing demands from business and consumer wireless users. 4G LTE is the first truly global standard for wireless wide area networks, and it is completely replacing the bifurcated 3G technologies. The competing standards in 3G resulted in multiple device SKUs, split R&D budgets and higher


manufacturing costs. The complete global acceptance of 4G LTE has led to very steep volume-‐‑based decline in network and device hardware. Another significant attribute is the acceptance of wireless as the “most reliable” method of communication. Wireless was originally just a convenient method of communicating when away from home or office, and was accepted as a secondary line. The simplicity and ubiquity of wireless led to the migration of minutes from the primary landline to the wireless phone. Service providers invested in reliability and customers noticed. Wireless voice became adopted as primary. Events like Hurricane Katrina and Super-‐‑storm Sandy demonstrated that wireless service was more reliable and much faster to restore than landlines. Services quality and reliability of 4G LTE is no longer at question. Consumers and Businesses are moving from LTE as solely a backup/service restoration type of technology towards mission critical primary use cases. The wireless ubiquity and unique security posture of 4G LTE can enable transformative business processes.

There are three factors to consider in determining if your location is suitable for LTE backhaul.

We have addressed Reliability. Throughout the world, the major service providers have definitely created sufficient overall core network reliability. In addition, most physical locations have cell coverage from multiple towers. This provides another layer of redundancy. If even further redundancy is required, dual modems with multi-‐‑Carrier support can be deployed. Signal Quality is a combination of signal strength, intersystem interference (the wireless operator’s cell site design) and “other users” impact to localized capacity. A simple site survey procedure with an LTE modem running various test traffic profiles can easily demonstrate if a location has sufficient signal quality. The final consideration is the business Application or Usage Profile. The majority of enterprise transactional applications are well suited for wireless backhaul without modification. Many enterprise video applications can also be


supported natively, while other higher resolution video applications can be supported with the inclusion of edge processing and content adaptation. Service Providers are growing their LTE wireless network capacity in support of the user demand. This network growth will be on 4G LTE. There have been recent discussions on 5G, but 5G will not appear anytime soon and when it does, it will interwork with LTE. The 5G evolution is being designed to provide localized very high bandwidth that complements the wide area 4G service. 5G will not replace LTE the way 4G replaced 3G.


Section 3 RAN Solutions Support Capacity and Efficiency

The Radio Access Network (RAN) is the linchpin of overall Network Capacity in any wide area wireless network. The 4G LTE RAN technology is the most advanced in the world. There are advances in LTE that are bringing more capacity and higher efficiency. The initial phase of the cellular industry was all focused on building out coverage. In that paradigm more sites, higher towers, and stronger signals led to more ubiquitous voice service. The more Bars the Better. The cellular service providers honed their processes and became very good at providing voice service coverage by building macro cell base stations. This initial phase was followed by a massive expansion of voice usage from landline migration and then the unprecedented adoption of wireless data. The focus of the wireless operators shifted from voice to data. The wireless carriers responded to the data tsunami primarily through spectrum augmentation and their tried and true macro cell buildout processes; add sites, add next carrier; add next spectrum band. Acquiring spectrum was paramount.


The previous capacity expansion methods for voice were not always suitable for data. Five Bars of coverage does not mean great data performance. Data optimization technologies were developed and deployed. A shift in design paradigm from voice centric to data centric began to take hold. The current focus of the wireless providers is now firmly data centric. Capacity and service quality are not enough. Ten times the capacity at ten times the cost does not enable transformation. The dramatic improvement in efficiency came via technology migration. For example, the migration from Analog voice to Digital voice (TDMA or CDMA) enabled an order of magnitude more voice capacity at half the cost. The “More for Less” synergy was an enabling factor in the wireless business transformation. What was originally a high cost mobile phone business for executives became a fully capable landline telephony replacement business for the entire consumer market. Similarly, the data service radio technology migration to scheduler-‐‑based High Rate Packet Data (HRPD) massively increased the spectral efficiency to allow Wireless Network Operators to market cost effective 3G data plans. The cost per bit to provide wide area wireless service took another steep decline. And now the Radio Technology Evolution has culminated with an extremely spectrally efficient OFDMA based 4G LTE technology as the single worldwide standard. In fact, 4G LTE has been shown to be within five percent of the theoretical Shannon limit. The Shannon theorem states that there is a maximum rate of information that can be transmitted over a communication channel in the presence of noise. As the noise decreases, the information rate also increases, but is bounded as shown on the chart.


So what is next? Are we at a capacity brick wall with LTE? No. We are nowhere near the brick wall of capacity, nor are we at the end of the declining cost per bit curve. However, the methods to achieve these gains are changing. New methods must provide both capacity and efficiency. The cost per bit will continue to improve. Service providers will grow their networks to support higher usage.

This chart lists some capacity enhancement methods being deployed now or in the near future in most major LTE operator networks.

Spectrum Augmentation Additional Spectrum is the most straightforward method of growing capacity. An initial coverage layer of spectrum with at least 10 MHz downlink and 10 MHz uplink is sufficient for high quality data services. This enables solid 2 to 4 MHz low latency wide area services. Additional spectrum is added in blocks of at least 5 MHz such as AWS or PCS frequency bands.

Scheduler Improvements The scheduler is designed to fairly apportion resources to multiple users based on their individual data queue and estimated Radio Channel conditions. Improvements in this process result in more efficient resource allocation and higher total throughput per base station.

Interference Cancelation Interference control is one of the most significant capacity and efficiency vectors. As stated earlier, LTE is within five percent of the Shannon limit. It is difficult to make future generational improvements if you are already at 95 percent of the maximum. However, the Shannon limit equation is for a channel in the presence

Capacity Enhancement Vectors

CapacityPerformance/Capabilities Cost/Efficiency

Spectrum Augmentation xScheduler Improvements x xIntercerence Cancelation x xIntercerence Reduction through Design x xCoMP x xC-‐RAN x xCarrier Aggregation x xSmall Cells (for efficiency/not small macrocells) xx xxMulti RAT and Helper Networks xx xxApplication Aware Scheduling xx xxEdge Processing (Fog Computing and caching) x x xxDistributed Architecture x x xx


of interference. Removing, avoiding or otherwise eliminating interference allows us to “move up and to the right” on the Shannon curve. Interference Cancelation may allow a typical LTE network to move from operating at 1 to 2 bits per second per Hz to a range of 4 or 6 or even 8 bits/s/Hz. This can double, triple or in some places quadruple the capacity of the RAN.

Interference Reduction through Design (SON) Optimized cell site location, antenna configurations and antenna downtilt will reduce the overall interference. As interference goes down, efficiency goes up, capacity goes up and cost comes down. Automation is being used to achieve optimal configurations. Real time automation tools are being implemented such as SON (Self Organizing Network).

Co-Ordinated Multi-Point (CoMP) CoMP is an LTE Advanced feature that combines signals from multiple base stations to take advantage of special diversity in the radio channel. The capacity gains come from a combination of Coordinated Scheduling, Coordinated Antenna Beamforming, and Joint Transmission.

C-RAN/Cloud RAN There are several new methods being deployed to bring the advantages of “cloud” to the Radio Access Network. C-‐‑RAN enables cost effective centralization of baseband radio functions (L2 and L3) with remote radio head units (L2 and L1). C-‐‑RAN in itself does not increase capacity, but it provides lower operating costs to the service providers and it enables implementation of capacity enhancement features such as CoMP.

Carrier Aggregation Carrier Aggregation enables a device to use frequencies from multiple bands. This improves peak speeds and greatly improves spectrum utilization. Verizon’s X-‐‑LTE service launched as multi carrier LTE (700 Mhz, AWS and PCS) was the first advancement towards carrier aggregation. Currently devices load balance across the carriers, but a device only operates in one band at a time. However, as devices become compatible, carrier aggregation will enable a single device to use multiple bands simultaneously.

Small Cell for Efficiency vs Coverage Early deployment of small cells was mainly to fill coverage holes. These small cell deployments are very inefficient. Implementing Small Cells with C-‐‑RAN and CoMP features enable in very high efficiency.


The scheduling decision for the microcell needs to be made at the same time and location as the macrocell scheduling decision. If the microcell scheduler cannot achieve 4 b/S/Hz then fall back and deliver over the macrocell. This coordinated scheduling method creates a system with minimal overlapping signal interference. Furthermore, the lower the interference, the higher the capacity. For this coordinated scheduling and fallback transport to work, we need a C-‐‑RAN transport architecture.

Application Aware Scheduling All applications are not the same. Why should they be treated the same as they transit the network? The Net Neutrality debate a few years ago incorrectly positioned this network management technique as unfair prioritization of one customer’s traffic over that of another. As the early rhetoric has lifted, it has becoming clear that there is absolutely a place for application aware scheduling. One simple example is the ability of the scheduler to deliver background applications (applications with no user interaction) at a “scheduling rate” that maximizes total system capacity instead of a rate that schedules average resource to each active device. While some may still argue over Net Neutrality, I argue that there is significant end customer benefit from Application Aware Scheduling. If Net Neutrality is really about benefits to the end user, then the customer value of application based scheduling will win out. Sometime in the near future, these methods will be implemented either in the applications themselves or via an Application Aware Scheduler. Either way, this will double or triple the effective capacity of the RAN.

Edge Processing and Distributed Architectures Implementation and strategic placement of content caches, content adaptation and distributed architectures for specific applications reduces latency and improves performance. Edge Processing (placing intelligent computing at the edge of the network) can parse, analyze and compress the data that is actually sent over the network. This eliminates unnecessary and redundant data transmissions.


While these techniques do not add physical capacity to the Radio Access Network, they do allow the network to perform better under the increasing data load. This results in a more efficient and less costly network.

Other Technology Improvements Information Centric Networking – Network routing decisions based on content instead of IP address Software Defined Networks (SDN) – Networks that can be automated and optimized for their specific use case instead a one generic network to support the average use case Network Function Virtualization (NFV) – allows the transition from monolithic telco cabinets-‐‑based networks to a webscale data center architecture and there are many other emerging solutions. Necessity is the mother of invention. The worldwide acceptance of LTE as the first truly global radio technology has created a global platform for innovation.


Section 4 The Business Landscape

We are in an age of business transformation that is unprecedented. Information and Communications Technology advances have created a “Disrupt or be Disrupted” business landscape. Businesses must have agility, low cost, rapid deployment, fail-‐‑fast-‐‑and-‐‑then-‐‑adapt based processes. At the same time, Network Security worries have never been greater. Data breaches can devastate a company’s brand image and bottom line. IT policies designed to secure the network can also hinder the ability to be agile and try out new services. Businesses should take advantage of wireless to increase their agility in delivering their end products or services. Overlay, or “Parallel” networks can enable these solutions without comingling with the tightly integrated enterprise IT network. While wireless has advantages in agility, there are often concerns with ongoing operation cost. While it is true that some continuous high volume uses cases make a wireless solution more costly than a fixed solution, many valuable use cases support a wireless only solution at similar or even lower cost than legacy fixes network data services. Even high bandwidth apps like video can be managed, especially in an enterprise environment. Intelligent Edge Processing and Content adaptation can enable even the most bandwidth intensive applications suitable for wireless delivery. Wireless data costs have declined dramatically and they are projected to stay on this trend.


Bandwidth Costs Declining ~27 percent annually since 1999. Source Mary Meeker Internet Trends 2014 report, KPCB. Competition among traditional wireless operators along with pressure from Cable companies and competitive Wi-‐‑Fi service offerings will keep this downward pressure on service pricing. The wireless operators are experiencing margin pressure, but as long as there is profitable demand there will be affordable pricing plans to capture the opportunity. As presented in the previous section, Capacity Solutions are available, and many of these solutions increase efficiency. This will provide the margins needed to enable the cellular service providers to continue the bandwidth cost trend.


Section 5 Applications

Every enterprise has multiple opportunities for 4G LTE across the WAN, and businesses today are actively leveraging 4G LTE to drive incremental revenue, improve customer experience, reduce operational costs, and enhance security. Applications include Machine-‐‑to-‐‑Machine (M2M) and Internet of Things (IoT), transportation and mobile/in-‐‑vehicle networks, temporary locations, failover, and primary connections. The majority of these use cases involve using 4G LTE as an overlay network to complement, augment or extend an existing enterprise network. As a primary source for connectivity, 4G LTE is high-‐‑performance in both a temporary and permanent environment, can be deployed quickly and in the majority of use cases, has a lower cost of ownership compared to wired lines. Businesses often require a network that can be deployed in hours, not weeks. Connecting new locations or branch offices traditionally requires running new wired lines—a process that can take weeks or even months to complete and is dependent on service providers’ strained appointment calendars. 4G LTE provides immediate, enterprise-‐‑grade connectivity on day one to support business devices and applications. It is also flexible enough to be deployed almost anywhere, reaching rural or remote locations that wired networks can’t. Whether a business is launching a temporary pop-‐‑up location, or needs to open a new location fast, 4G LTE is a natural fit. Additionally, enterprises are also finding value in 4G LTE as permanent primary connectivity. Businesses leverage the flexible connectivity to optimize and pool data usage among multiple distributed locations, deploy networks faster, and manage the network remotely to reduce the need for on-‐‑site IT support at every location. Of course, more and more mobile/in-‐‑vehicle applications are being deployed by enterprises delivering “close to the customer” goods and services. Regardless of whether an enterprise leverages 4G LTE for temporary or permanent primary connectivity, each can improve both network efficiency and security. Businesses can offload non-‐‑core internal applications like customer WiFi, PoS systems, and digital signage onto physically separate Parallel networks to free up bandwidth from corporate networks. This networking approach can also be used to remove third-‐‑party applications from a corporate network, such as kiosks, security systems, and HVAC controllers to keep their primary networks and customer data secure.


In all cases, 4G LTE solutions are highly flexible, easy to deploy, highly secure, and non-‐‑disruptive to existing networks.


Section 6 Conclusions

The current outlook for 4G LTE is positive. LTE is here to stay. There are significant capacity enhancement solutions being implemented, and many of these solutions simultaneously improve efficiency (lowering the network cost per bit). This, in conjunction with increased user demand and competitive price pressures will keep consumer and business prices affordable. The ubiquity, reliability and deployment flexibility of wireless makes 4G LTE it a natural and viable transport technology to support many demanding enterprise use cases. These features of LTE along with the agility that enterprises must display in the current business environment, makes LTE a practical and desirable first choice WAN solution for distributed/branch and remote locations.

Bio Chris Neisinger is the former Executive Director in the CTO Organization at Verizon. In this role, Mr Neisinger and his organization were responsible for the technical evolution of the wireline and wireless networks. This includes evaluation and development of new technologies and architectures. He has led Verizons efforts in 3G and 4G wireless architiecture development, IMS and VoLTE, Cloud, Analytics and M2M.

4G LTE as a WAN Solution for Enterprise

Documents