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LTE Market,

Technology,

Products

Dr Nick Johnson, CTO,

Issue 1.1, ip.access, February 2012


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LTE Market, Technology, Products - 2 - ip.access 2012

EXECUTIVE SUMMARY 3

Background 3

The Problem 3

The Solution 3

The ip.access Market Vision 3

INTRODUCTION 5

Market Overview 5Global Observations 5North America 6Japan & Korea 7BRIC 8Developing World 8Europe 8

SOLUTION OVERVIEW 9

Summarising the Benefits 9

Solution Architecture 10

PRODUCT FOCUS 18

The E-100 LTE Access Point 18

Gateway 20

Network Orchestration System 20

TECHNOLOGY TOPICS 21The Multi-Standard Basestation 21Inter-RAT Mobility 21WiFi integration and IP Flow Mobility 22Content Aware Scheduling 23Network Offload (LIPA, SIPTO and LIMONET) 25

The Importance of FAPI 26High Performance, Low Cost, Low Power Consumption Baseband Silicon 26Wide Band, Technology Agnostic RF Silicon 26Self-Organisation, Self-Optimisation 27IMS access 27

SUMMARY 29


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Executive Summary

Background

ip.access is the world leader in W-CDMA femtocell technology, and has been serving the indoor

small cell market since 2000. Its GSM picocell technology (trademarked nanoGSM) andcorresponding 3G technology (nano3G) are accepted and operating in over 60 mobile networkoperators worldwide.

The Problem

As the world enters the 4G age, a series of new challenges and opportunities present themselves.

The demand for mobile data is doubling year-on-year is projected to continue

As QoS demands increase with more streaming and high bandwidth interactive content,networks are being dimensioned more for peak data throughput than average

With 70% of calls originating or terminating indoors, serving those users with sufficientradio and core network capacity from the macro network will get harder and harder

Spectrum is being freed for licensing, but in more and more fragmented bands

The migration towards 4G cannot rely solely on new spectrum as in previous generations,but must re-farm and coexist in spectrum already in use for older technologies

Operators continue to struggle to contain operational costs in a climate of flatteningrevenue growth and steepling customer expectations.

The Solution

In recognizing the key pain points affecting the industry today, ip.access offers a new generation ofradio access network, nanoConverge. The key features of nanoConverge address those painpoints head on:

LTE, 3G and WiFi capable simultaneous multi-standard small cell basestations (nanoCells)deliver high rate data to customers over the most economical, highest performing radiointerface with a roadmap to IP Flow Mobility.

These same basestations are offered with high-order multi-band capability typically fourband coverage allowing operators to serve regions covered by different licensedfrequencies with a single small cell access point for maximum logistical efficiency.

Innovative architectural solutions allow data delivery with minimum core network loading,while satisfying lawful intercept regulations.

High functional Operations and Maintenance solutions, coupled with distributed SelfOrganising Network (SON) features in the basestation, delivered via a NetworkOrchestration System (NOS) help operators minimize their operational expenses whiledelivering a highly optimized performance solution.

The ip.access Market Vision

ip.access specialises in providing small cell solutions for indoor enterprise, public coverage andresidential applications. We also recognize the commonality between public indoor and publicoutdoor coverage, and enable our partners to address this important outdoor segment (for bothdeveloped and emerging markets) with small cell modules to be incorporated within their existingstrand-mount, satellite, marine, aero or security products.


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70% of mobile voice and data traffic is generated from inside buildings, divided roughly 50:50between enterprise and home. By focusing on the in-building space, we are following the paretorule to make maximum contribution to network performance from our particular market position.

Our small cell technology is used by Cisco to deliver AT&T's 3G residential femtocell solution

(branded 3G MicroCell)the worlds largest small cell deployment by volume and by value.

Our LTE-A technology, including Gateway and Management System, coupled with our existingnano3G HSPA+ technology and enhanced by 802.11n/ac WiFi provides the perfect solution for ourcustomers serving the indoor space.


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Introduction

Market Overview

The world is moving towards 4G-LTE-A as its cellular radio technology for the foreseeable future.

However, different parts of the world are moving at different rates and with different priorities, andthere is the important distinction everywhere between the outdoor macro and the indoor small cell

in which ip.access has built its business.

Global Observations

The Cisco Visual Networking Index (VNI) shows the demand for mobile data doubling year-on-year. Importantly, it has shown this trend consistently for the last several years.

Figure 1 - The Cisco VNI, Fixed and Mobile

In terms of trend information, this graph shows two further key pieces of information

In 2015, mobile (cellular + WiFi) will overtake fixed data delivery

Cellular data is growing at 92% CAGR, with WiFi at 39% CAGRo cellular data will draw level with WiFi by the end of the decade

Additionally, there are multiple press reports, and our first-hand experience in some markets, that

signalling capacity in mobile networks is being reached already, especially where smartphonesare in heavy use. The traditional 3G radio access network (RAN) architecture is particularlyvulnerable to this (the RNC is vulnerable to signalling overload from the rapid data start-stop ofsmartphone app behaviour). It is one of the drivers towards the femto and LTE RAN architecture,which does not use an RNC and distributes the RAN signalling to the Access Point.

Figure 2 - Fierce Wireless reports Credit Suisse, July 2011


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While average monthly mobile data usage is, in fact, still fairly low, the peak load is beginning tostrain the capacity of the core networks. This peak loading is becoming a greater problem asoperators seek to offer services requiring high Quality of Service (QoS)

1compliance, and their

networks need to be dimensioned for peak load, rather than average. This trend is forcing offloadstrategies in two directions. On the one hand, operators are offering WiFi services as an

alternative/adjunct to mobile cellular. Secondly, RAN offload strategies within mobile networks arebeing standardised to allow mobile data to be carried without loading the core.

In terms of radio layer congestion in the face of the yearly data doubling around the globe, we alsosee a requirement to exploit all of the spectrum assets accessible to an operator. Therefore multi-standard operation, including the integration with WiFi is key to the long-term success of thesolution. This allows operators to extract value from their spectrum licenses in a way not possiblein previous generations of technology.

North America

Within the North American market, LTE deployments are furthest ahead, but are still relativelylimited in scope, with only major cities being covered (and those only partially) at the time of writing.

Key trends are clear already from this market.

The requirement for multi-standard

Our lead customers are committed now to a multi-standard world. They recognize thatthere is so much invested in existing GSM and 3G infrastructure that the idea of LTEdisplacing it is not tenable.

The requirement for multi-band (the Single SKU requirement)

Within North America, spectrum is licensed on a Major Trading Area (MTA) basis, so thatdepending on exactly which MTA a device is located in it may or may not be licensed to

use particular spectrum. To try and manage the logistics of multiple single-band devicesbeing deployed into particular locations, given the expected scale of small cell rollouts, isa frightening prospect. The only feasible solution is to make the basestations capable ofoperating in all the licensed bands, so that the device can select at run-time which band tooperate on it can never be in the wrong MTA for its capabilities. This so-called SingleSKU requirement is a key product and technology driver, and has its equivalents in otherparts of the world.

The requirement to support spectrum re-farming

In the US, spectrum is not licensed on a specific technology basis, and it is up to the carrier andtheir suppliers to agree the usage. The idea of re-farming is actually a misnomer in this context,

since the operators are free to operate any technology in any band without any special regulatoryprovision. For instance, we are operating 3G femto in spectrum on which 2G basestations are

1We see the Quality of Service (QoS) discussion is being modified by the introduction of the concept ofQuality of Experience (QoE), where the end-users experience of the content is measured, rather than theperformance of any particular data service. This development is key in ip.access response to the data offloadand network performance requirements as well see below.


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already deployed co-existing quite happily. It is only in the two 700MHz bands that we expectLTE to be deployed exclusively. In all other bands (PCS1900, Cellular 850 and AWS 1700/2100)we see standards co-existing within the same bands, and even, as described above, in the samechannels. We expect this example to become the norm, not just in North America but around theworld, where traditional spectrum allocations to specific technologies are becoming obsolete. For

example, Europe has already moved to allow re-farming of GSM 900MHz spectrum for 3G.

The focus on Enterprise and metro over residential

While the business case for 3G residential femto has been proven, and ip.access is supporting thebiggest femto deployment in the world, the drive towards LTE residential femto will take someyears to bear fruit. The LTE technology base will take several years of Moores law evolution tosupport the magical $100 price tag. The need for LTE in the home does not appear to be a priorityfor North American operators. When it does appear, it is likely that it shares the samerequirements in terms of multi-standard and multi-band capability as the enterprise and metroequivalents placing further pressure on its pricing, and pushing its earliest arrival date further out.

LTE as the Value Play

LTE has been traditionally featured as a performance solution, but at least one operator(metroPCS) is deploying it as the lowest cost way of deploying a mobile data network. metroPCSsells exclusively contract-free, pre-pay subscriptions. Its subscribers deliver the lowest ARPU in itsmarket, yet by a selective deployment of LTE alongside its CDMA network, it is offering acompelling combination of voice and data services to deliver a successful business. Its voiceservice is based on CDMA 1x, but its data service is built around LTE 1.4MHz in the AWS band.This configuration is possible because of the unique heritage of the 3GPP2 operators (Verizonincluded) in that the voice and packet data services are on wholly different radios within thenetwork and handset, with no integration at the physical layer. For the 3GPP2 operator, theintroduction of LTE as an adjunct to or substitute for EvDO is entirely natural, and as far as we cansee, entirely successful.

The requirement for location verification

As remarked above, spectrum in North America is licensed on an MTA basis. It is a licensecompliance requirement that basestations operate in the spectrum that is appropriate for the MTAin which they are located. While MTA boundaries originally ran through sparsely populated areas,the pace of development has now placed some MTA boundaries within urban or suburban centres.For small cells, which may be deployed by enterprise IT staff or even end-users, rather thancarrier-trained experts, it is an essential requirement to verify where the basestation is to highdegree of accuracy.

This is in addition to the requirement to accurately locate the originator of an emergency call (theso-called E911 requirement). While the E911 requirement for residential femto may be satisfied by

simply knowing the location of the basestation (essentially the same requirement as the MTAverification requirement), as small cells get larger for enterprise or public indoor use, its expected

that the E911 requirement will rely on existing E-TDOA equipment or direct GPS interrogation ofthe handset, rather than location verification of the basestation.

Japan & Korea

The initial LTE focus in many countries will be on the macro network rollout, with small cells beingdeployed later as an overlay for hot-spot capacity and coverage. However, Japan and Korea are


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Solution Overview

Summarising the Benefits

Product/Feature Benefit

A new generation of multi-band, multi-standardbasestations, aggregating LTE, HSPA+ andWiFi 802.11n

Multiplies rather than sums spectrum andtechnology assets.Multiple technology support giveslongevity in the face of spectrum re-farming.

Core design capable of two channel (+WiFi)operation on any of four bands

Removes logistical deployment issuesany basestation can go anywhere

The four bands can be selected for US, Europeor other specific territory requirements

Global coverage with minimal logisticalcomplexity

Roadmap to LTE-TDD Further increases spectrum options,especially in China

A gateway and management architecture thatallows self-organisation and global optimisationof performance

Minimises cost-per-bit of data delivery,while maximising end-user performance

Supporting the 3GPP self-organisation featuresfor LTE and 3G2in the basestation,

In the NOS (NOS assisted SON) andIn the OSS (via SONiX)

Minimises network operational expenseon a network wide basis (not just thesmall-cell layer)

Open interfaces to support integration with 3r

party macro RAN and existing operator OSSsolutions

NOS northbound interfacing

Allows interconnect with existing NMSsolution to minimise integration costs andmaximise ongoing opex savings

Innovative IMS support options Enables a migration to a single, IMSbased service environment, with longterm savings in multiple core networkmaintenance.

Network offload architectures (3LIPA, LIMONET

and SIPTO and Content Aware Scheduling) tooffload the mobile core network.

Minimises cost-per-bit of data delivery,while maximising end-user performanceOnly a fraction of mobile data needs totransit the coreReduces operational cost associated withthe dependency on QoS managementacross multiple domains

Targeted at real-time streaming, interactive,secure local data access and othermetro/enterprise services

Maximises service revenue from thevaluable enterprise segment. Provides aplatform for future residential offerings

2 NOS = the ip.access Network Orchestration System, SONiX = SON Information Exchange

3 LIPA = Local IP Access, LIMONET = LIPA with mobility, SIPTO = Selective IP Traffic Offload.


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Unified architecture for 3G, 4G and WiFi Minimum gateway count reducesoperational expense, real-estate andpower requirements in the data centre.

Inter-Radio-Technology (IRAT) mobility toensure dynamic, balanced utilisation of the

multiple radios

real-time balance is the key to highthroughput, high quality radio

performance and is the optimal way tomultiply three optimal radio technologies.

Roadmap to IP Flow Mobility (IFOM) Gives the ultimate flexibility in deliveringdata to the end user using multiple air-interfaces simultaneously.

Solution Architecture

The basic solution architecture is shown in FIGURE 3Error! Reference source not found..

The day-one architecture shown in Error! Reference source not found. includes the key features

for a high-performance Radio Access Network in a modern heterogeneous network (HetNet).

All the basestations are hosted in a common framework, with a single gateway and managementsystem operating all devices, 2G, 3G and 4G, residential femto and pico class small cells forenterprise or metro application.

The network is flattened, with all RNC functions hosted within the 3G basestations. Thearchitecture includes a HNB-GW function to provide aggregation to the core, as required by the3GPP standard.

The S1 interface from the E-100 LTE device can be aggregated within the gateway or may bedirectly routed from E-100 to the core via the SecGW. (There are good value-add reasons forusing a gateway SON interworking and QoE/QoS management among them which we describe

in more detail below.)

Figure 3- The Basic Network Architecture


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The X2 interface between the E-100 LTE node and the macro network is routed via the gateway,which can provide some aggregation of signalling, and processing of SON measurements asdescribed more fully below.

The Network Orchestration System (NOS) provides a layer management function, allowing all the

subtended basestations of whatever technology to be managed from a common system. The NOSprovides ACS (TR-69 based mass provisioning) for femto style deployments as well as traditionalFCAPS for enterprise and metro style deployments. The NOS also manages the other nodes inthe layer, including the gateway, the NTP servers and the security gateway.

This architecture is enhanced over time to include the architectural and radio-bearer managementfunctions, as follows.

FIGURE 4 - NANOCONVERGE GATEWAY WITH SELECTIVE TRAFFIC OFFLOAD

With the inclusion of core network offload features, the architecture of the gateway is enhanced toinclude a SIPTO (Selective IP Traffic Offload) port, as shown in Figure 4. Note that there is oneSIPTO port for all technologies, including 3G and 4G and can similarly provide a route for WiFitraffic where this option is fitted within the E-100. Such technology-independence provides animportant simplification for IP network engineering and deployment management, as well as asingle node to connect billing and lawful intercept gateways.


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Figure 5 - nanoConverge with Enterprise Gateway on t he Customer Premises

And for enterprise deployments with scale, an Enterprise Gateway is added to the architecture asshown in Figure 5.

The purpose of the Enterprise Gateway is to provide a single point of management andadministration within an enterprise. For small enterprises that only require one or two basestations,the features can be hosted within the E-100 itself.

Some key points of the Enterprise Gateway

It is a software application that can be hosted on an enterprise router platform it needs nospecial hardware beyond some IPSec acceleration.

The gateway hosts IPSec termination for devices on the enterprise network, including I-WLAN compliant WiFi devices. It also originates an IPSec tunnel to the core networkgateway. All telco traffic on the enterprise LAN is therefore completely secure. It is only inthe clear when intended to be so for direct internet access or other enterprise applicationuse.

The embedded LIPA/LIMONET function allows users to access local enterprise datasecurely and quickly, and with zero tromboning to the mobile core network.

The IRAT Mobility function operates on the enterprise cluster to ensure that thebasestation load is balanced one to another, and also balanced from one technology toanother to ensure global maximum network performance.

The IP Flow Mobility (IFOM) function allows data streams to be forked (downlink) andrecombined (uplink) within the gateway and routed over the most appropriate air-interfacesto the IFOM handset (note the plural air-interfaces). The architecture allows aggregationof IFOM branches across different basestations so that resources within the network aretruly balanced.

The V-GW function is a VoIP signalling and codec implementation that allows mobileintegration with the enterprise fixed voice network. The V-GW might use native VoIPapplications within the handset (where the LIMONET gateway allows VoIP with mobilitywholly within the enterprise). It can also provide an interworking function between VoIP onthe enterprise LAN and classic Circuit Switched Voice on the mobile segment.


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How are the benefits summarised above implemented in the ip.access solution?

Benefit Network ImplementationMultiplies rather than sums spectrum andtechnology assets.

Multiple technology support gives longevity inthe face of spectrum re-farming.

The E-100 basestations are equippedwith Inter-Radio Access Technology

(IRAT) mobility functions. Spectrum andthroughput resources are balancedbetween the network technologies withinthe basestation.In hardware terms, the basestations arebuilt with two independent radio channelsthat may be tuned anywhere within fourselected, geographically optimal bands.The two radio channels may operate inany band, using 3G/HSPA+ or LTE, thusallowing the basestation to continue inuse even after the spectrum has beenrefarmed.

Removes logistical deployment issues anybasestation can go anywhere

The ability to tune within up to four radiobands means that licensing restrictionsas to spectrum are removed. Thebasestation is effectively no longer band-specific or 3G/4G specific.

Global coverage with minimal logisticalcomplexity

The underlying technology in thebasestation is intrinsically wideband, andsupports FDD and TDD operation. Thepower and filtering requirements for anygiven geometry are restricted to a subsetof the circuit, so delivering a device into ageography with specific bandrequirements is greatly simplified.

Further increases spectrum options, especiallyin China

The ability of the underlying basebandand RF technology within the basestationto support TDD allows deployment inregions with TDD requirements.

Minimises cost-per-bit of data delivery, whilemaximising end-user performance

The network architecture supports LIPA(local IP access), LIMONET (which isLIPA with enterprise mobility) and SIPTO(for traffic routing optimisation). Suchfunctions may be hosted within thebasestation itself, the enterprise gatewayor the core network gateway formaximum flexibility. The features allowthe data to be routed to its destinationwithout transiting the core network amajor cost saving.


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Minimises network operational expense on anetwork wide basis (not just the small cell layer)

The SON implementation within thenetwork is done at three levels.

Within the basestation, specificSON features allow thebasestations to configure

themselves within constraints setby the network operator

Within the NOS, optimisationsare performed, based on KPIspassed from the gateway, andconfiguration passed back to thebasestations, specifically forclusters of interacting cells withinthe management view of theNOS

Northbound from the NOS, theNOS itself passes KPI data to theOSS and core network

optimisation functions, so that thesmall-cell layer can be optimisedwithin the context of the wholenetwork

Such automation support reduces to aminimum the requirement for manualintervention in the operation of the smallcell network.

In terms of RF layer optimisation, inlarger enterprise clusters, the inter-technology load balancing may be hostedwithin an Enterprise Gateway to ensureglobal optimisation of performance andspectrum utilisation within the enterprise.This has the side benefit of minimisingRF power settings, and thereforeminimising RF interference within anyumbrella macro coverage.

Allows interconnect with existing NMS solutionto minimise integration costs and maximiseongoing opex savings

The NOS provides a rich suite ofnorthbound interfaces for configurationmanagement, fault management,localisation and diagnosis andperformance management. 3GPPstandard interfaces are used throughout,including support for popular industrystandards.


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Enables a migration to a single, IMS basedservice environment, with long term savings inmultiple core network maintenance.

With the multiple radio interfaces withinthe basestation all able to pass their datathrough a single IP gateway (by virtue ofthe LIPA, LIMONET and SIPTOfunctions), this allows a very simple

integration with the IMS or other unifiedIP based service delivery platform (suchas an enterprise server). The single pointof interconnect allows the user to registerand be paged through a single port, andthe particular radio access technologythat is chosen for the session is up to thebasestation. This reduces the role ofeach of the core networks in the serviceprovision, and allows the operator tofocus their service innovation resourcesin a single place (the IMS) rather thanhaving to reduplicate such resources over

multiple core networks.Minimises cost-per-bit of data delivery, whilemaximising end-user performance

The key feature of the LIPA/LIMONET/SIPTO functions is that only a fraction ofmobile data needs to transit the core.Also, that fraction can be dynamicallyselected, according to service routingrequirements and lawful intercept andother regulatory requirements. In thisway, the core network can be focused onmaximum revenue generation andregulatory compliance function where thisis necessary. All other low revenue trafficcan be delegated to the shortest, or

cheapest route according to policy andcurrent network conditions. The LIPAand related functions within the solutioncan be configured dynamically with thisrouting information via the NOS.

Reduces operational cost associated with thedependency on QoS management acrossmultiple domains

This is the Content Aware Schedulingfeature. This feature enhances and canin some cases offset errors in outer-packet QoS marking by queuing dataacross both lossy interfaces (thebackhaul and the radio) according to itsimportance to the content in question. Itexists within both the gateway and thebasestation to ensure that the schedulingalgorithm at the gateway is accounting forlosses in both backhaul and radiointerfaces in calculating its schedulingscheme.


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Maximises service revenue from the valuableenterprise segment. Provides a platform forfuture residential offerings

The feature set is specifically designedto offer high performance and secureaccess in an enterprise environment (seeFigure 5 above). While the solution istuned for performance in the enterprise,

the much greater data volumes in theconsumer space mean that the offloadand RF load balancing techniquespioneered here will be equally valuable tothe network operator and consumer alike,when applied in the residential space.

Minimum gateway count reduces operationalexpense, real-estate and power requirements inthe data centre.

The gateway is a single device coveringall technologies. The scale of thegateway is determined solely by the scaleof the traffic it is having to manage.Coupling the gateway investment to thetraffic rather than to the technology is theright way forward.

Real-time balance is the key to highthroughput, high quality radio performance.The optimal way to multiply three optimal radiotechnologies.

The essential idea here is that any userof the solution, in order to get bestservice, should be able to choose thelightest loaded network option. Themobility, load-balancing and IP FlowMobility features within the basestationand Gateway functions mean that theuser is never camped on a radio that ismore heavily loaded than another.Therefore, when they start a call, thechance of a directed retry to a bettercell/better RAT is optimally minimal.Therefore they get best performance, and

the network operator gets minimalsignalling load.


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Gives the ultimate flexibility in delivering data tothe end user using multiple air-interfacessimultaneously.

This is the IP Flow Mobility feature(IFOM). The IP Flow Mobility gatewaymay be implemented within thebasestation for single cell operation andmay be hosted within the Enterprise

Gateway for clustered operation. In bothcases, the IFOM network entity peerswith a corresponding UE entity, and thetwo signal to each other during thestartup phase of the IP Flow, whetherfurther radio interfaces need to beestablished. For instance, if the flowstarts on LTE, the two entities decidetogether whether the flow should continueon LTE, should transition to WiFi, orshould be aggregated with WiFi forsuper-high bandwidth applications. Otherradio combinations are possible, and the

policy decisions regarding their relativepriorities is configured, but the decisionmaking is done in real time using thepolicy and also real time measurementsof network load and radio link quality.


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Product Focus

The E-100 LTE Access Point

Reproduced below is the datasheet for the E-100 basestation. Note that this is advance

information, subject to change without notice.


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Gateway

The Gateway for the ip.access LTE solution is identical to the nanoGateway 300 gateway alreadyin use for 3G femto and enterprise systems. The reader is referred to existing documentation forthat product.

Network Orchestration System

The reader is referred to existing product documentation on the Network Orchestration System.


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TECHNOLOGY TOPICS

The Multi-Standard Basestation

The availability of the highly integrated, high performance baseband processing, with RF agnostic

modulator chips allows us to introduce multi-standard basestations with very compact form factor,for enterprise as well as metro applications. As the technology develops, the residential form factorand price point will similarly come within reach for these multi-standard devices.

The key point here is the ability for a single device to carry user data in a balanced way, over themost appropriate radio, whether that be LTE, HSPA+, 802.11n or a combination of the above. Themulti-standard, multi-band basestation allows the operator to trunk their radio interfaces in a waythat has not been possible in the past, and get the associated trunking gains of capacity in theradio that they have been used to in the fixed segment for years.

Inter-RAT Mobility

Key to achieving the radio layer trunking gain, and implementing the Mobility Load Balance SON

feature, is the ability to move users from radio layer to radio layer smoothly, with no interruption ofdata flow. ip.access has a unique framework to achieve this, taking account of multiple factors toachieve the load balance, as shown in the diagram.

In previous generations of device, Inter-RAT mobility is implemented, but it is strictly betweenbasestations for instance handover from femto 3G to macro 2G. This is rather simply calculatedon the basis of UE measurements and, to some extent, UE service requests, as shown in Figure 6.

Figure 6 - Classical Inter-RAT Mobility

However, the co-existence of multiple RATs serving essentially identical user populations creates

new balancing problems/opportunities, as shown in Figure 7.

Layer balance (occupancy balancing)o To minimise the chances of blocking, and to maximise the offered throughput to

each user, the occupancy in each layer should be balanced according to thetechnology demands within the population


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o Each new call should experience the same chance of blocking (or throughputavailability), regardless of which layer it originates from

o This is the function of the Layer Balance module Service/user prioritisation

o Decision making is biased by policy factors certain services and users, may be

preferentially steered to certain technologies according to QoS CPU load

o In the multi-standard basestation, moving devices between layers may have aCPU architecture dependent effect on the total CPU load. Therefore, we

provide static limits of layer loads, adapt and predict usage to manage load to a maximum operational level

UE measurements and events (RF resource balancing)o The UE population link budget is now managed dynamically, so that layer changes

take into account the total link budget quality

Figure 7 - IRAT Mobility with Load Balancing

WiFi integration and IP Flow Mobility

In addition to the LTE and HSPA+ air interfaces, adding 802.11n to the mix allows an even greaterradio layer trunking gain. 3GPP recognises this, and has an active work item called IP FlowMobility (IFOM), as shown in the diagram.


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PGW1

non-3GPP

access

3GPP

access

PDN1

UE

PDN connection #1

flow #1

flow #2flow #3

Figure 8 - IP Flow Mobility (IFOM)

ip.access sees IP Flow Mobility as the logical culmination of efforts to provide technology thatallows the operator to use their spectrum assets in the most cost-effective, spectrally efficient andperformance enhancing way possible. By trunking all of the air-interfaces, cellular and unlicensed,and providing the technology to move smoothly between them to allow a state of balance to besustained between them, we are close to the theoretical limit of capacity provided by these threeair-interfaces which are, in themselves, also close to their own respective theoretical limits.

Content Aware Scheduling

LTE offers a much richer mix of QoS categories for its content, but multiple factors affect the abilityof a carrier to reliably offer services based on these QoS categories:

Appropriate QoS marking of the content may not always happen. In particular, wherecontent is a mash-up from multiple sources, the QoS marking of the stream may in practicebe some arbitrary value, unrelated to the QoS requirements of the sub-streams.

o Example: a web page that contains YouTube content may be transferred using theQoS appropriate to the static content of the page. The streaming video that theuser is interested in may carry the same QoS marking, and the user experience ofthe streamed content will be poor.

The content may be marked appropriately for the LTE air-interface, but, given the desire tooffload to or aggregate with other radio technologies, the LTE QoS markings may not be

mappable to a WiFi or HSPA+ QoS queue.o HSPA+ defines 4 traffic classes and 13 QoS attributes whose associated

complexity leaves them often unusedo LTE standardises on 9 QCIs (QCI = QoS Class Identifier an abstraction of a

concrete QoS class) and the mapping between the LTE QCI and the 3G TrafficClass + QoS attribute setting is ill defined.

Given the imperfections of the backhaul interface, the air-interface QoS marking may berendered meaningless or impossible to achieve by packet loss or retransmissions in the IPnetwork between the content and the basestation.

o Transit networks may or may not respect QoS markings.


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o Effectively, we are asking a single QoS scheme to define behaviour across twolossy networks the backhaul and the radio.

One way of cutting through this complexity is to introduce the concept of Content AwareScheduling, defined on a stream by stream basis, between the data source and the UE, and

implemented jointly on the core network gateway, any intervening gateways (such asLIPA/Enterprise gateways) and the LTE basestation.

Figure 9 - Content Aware Scheduling

The scheme is illustrated in Figure 9, where the top half shows the way things are done today. TheUE requests a QoS class at the time of PDP context activation. If the session is invoked from aweb-browser, then the QoS class will invariably be Interactive/Background or similar. So, if youbrowse to YouTube for instance, and expect Streaming QoS then youll be disappointed. Theres

nothing in the system to saythis content is streaming video Ill change QoS class. This is oneof the reasons why such content has its own application in the smartphone world. YouTube andother content providers with specific QoS requirements now give you the option of using theirspecific phone App, which knows that you are looking for Streaming QoS and a certain bit rate, andcan therefore request it when the PDP Context is set up.

Even so, for all the reasons described above, this may not be enough. The point of Content AwareScheduling is to subdivide the QoS requirements of specific content streams, based on theirencoding or other information, and can queue them accordingly within QoS queues that the

gateway sets up to the basestation on its own assessment of the content, not on the semi-blindrequest of the PDP Context Activation. Of course, the QoS management within the basestation issomewhat determined by the QoS class request of the PDP Context, but even so, there is enoughlatitude within the specifications to make a significant improvement in performance of theapplication as perceived by the user (the Quality of Experience or QoE), to make the exerciseworthwhile.


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Network Offload (LIPA, SIPTO and LIMONET)

Network offload architectures, such as LIPA, SIPTO and LIMONET, are key to realising thepotential of the radio interface, even when the backhaul to the basestation or enterprise cluster is oflimited bandwidth. The LIPA and LIMONET architectures in particular allow enterprise users to

access local data and services without having to traverse the mobile core.

Figure 10 illustrates the LIPA architecture. The key element is the Local Gateway (L-GW in thefigure) whose presence is signalled to the SGSN as a potential GGSN at the time of PDP ContextEstablishment. The SGSN can then select the L-GW for this PDP Context, according to somepolicy rules within the core network. This is a relatively simple architecture, effective at offloadingthe core, but its defining characteristic is that the L-GW is part of the H(e)NB. When the userhands out to another cell, the data path is broken, and so the PDP Context must be re-establishedon the new cell. Thus, this architecture does not support mobility.

Figure 10 - Local IP Access (LIPA)

An improvement on the LIPA architecture of Figure 10 is shown in Figure 11. This is one of twoarchitectures being considered by 3GPP currently, but is seen as preferred and is therefore likely tobecome standardised. The essential point here is that it separates the L-GW from the H(e)NB andtherefore allows the user plane to be routed to the L-GW from any other basestation also reachablefrom the serving gateway (S-GW, or SGSN in the 3G case) and from which the user plane isroutable.


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band in the 600MHz 3.6GHz range and configure to any bandwidth up to 20MHz, with 2x2 MIMOsupport included. The chips also support 3G modulation and are both ideal candidates for a multi-standard product.

Self-Organisation, Self-Optimisation

Product and system features to allow the RAN to organise and optimise itself are a key technologyfor LTE and ip.access has an active programme to implement and deliver self-organising featuresinto the first generation product. Key differentiators:

Inter-cell Interference Coordination (ICIC) for Physical Resource Block coordination with

macro neighbours

Classic ICIC is intended for interference coordination at cell edges. We enhance the techniques,noting that small cells actually wont always be at the macrocell edge. In doing so, we use existing

ICIC primitives to optimise the technique for small cell deployments.

Automatic Neighbour Recognition (ANR)

ip.access pioneered the use of an embedded downlink receiver (Network Listen) to detect the localradio environment. Our starting point for ANR is the detection and decode of neighbour celltransmissions to set up the initial neighbour list for reselection and hand-out. Our Network Listenreceiver for W-CDMA also decodes GSM, and similarly our LTE NWL receiver decodes W-CDMAand GSM also. For CDMA markets we work with partners to enable ANR to 1x cells.

Other SON techniques

The other 3GPP SON techniques (including Mobility Load Balancing (MLB), Mobility RobustnessOptimisation (MRO), enhanced ICIC (eICIC), Physical Cell-Id (PCI) selection and so on) aresubject to active R&D, with patent filings ongoing. Further details on all these SON techniques areavailable on request.

IMS access

One consequence of the aggregated RAN vision, coupled with the data offload architecturesenabled by LIPA and LIMONET, is an architecture that places the RAN, and in particular thebasestation at the centre of the network, in terms of the actual service delivery to the userequipment.

The concept is to connect the service client (IMS enabled) in the UE via a generalised PDP contextto the service provider in the IMS via the nanoConverge RAN. The IFOM function within thebasestation peers with the connection manager in the UE to carry that PDP context over the bestcombination of radio interfaces LTE, HSPA+ and/or WiFi and deliver it to the IMS gateway viathe local LIPA/LIMONET gateway.

This architecture enables the acceleration of the transition to IMS hosted services, common to allradio interfaces, since we are simply using the mobile core networks as authentication and mobilityservers for the radio bearers. The actual decision as to which bearers to use is negotiateddynamically between the UE and the RAN at the start of the service and adapted continuously forthe duration of the service.

Additionally, by including IMS to CS voice interworking within the basestation, we can serve R99handsets on the same infrastructure.


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With nanoConverge, operators can accelerate their transition to a common IMS service platform,and reduce or even completely avoid continued investment in individual mobile core services. Allfuture service creation investment can be focused on the IMS as a single platform for all the radiotechnologies in a carriers portfolio.

The basic architecture is shown in Figure 12.

Figure 12 - IMS Access using the ip.access E-100


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Summary

As we move into the era where the consumption of mobile data becomes the norm, rather than aniche, indoor small cell deployments will become key for any operator. The clear preference ofsubscribers to take their data indoors makes a high performance indoor cellular network layer a

necessity. ip.access' nanoConverge small cell Radio Access Network offers a powerful and flexiblesolution.

By a careful analysis of the market trends, and drawing on years of experience serving top tieroperators in enterprise markets, ip.access has identified an optimal suite of products, architecture,technology and features. This combination is easy to deploy, maximises the network performanceby offloading the macro radio and core, and minimises operational costs by providing abundantself-organisation.

In the network operator toolkit of the future, there will be no bigger wrench.


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ip.access ltd

Building 2020, Cambourne Business Park, Cambourne, Cambridge, CB23 6DW, UK

T +44(0)1954 713700 F +44(0)1954 713799 [email protected]

www.ipaccess.com

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