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UMTS/HSPA to LTE Migration Maximize the life and value of existing assets while achieving a true 4G network WHITE PAPER

49461244 UMTS to LTE Migration White Paper

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UMTS/HSPA to LTE Migration Maximize the life and value of existing assets while achieving a true 4G network

WHITE PAPER

2 WHITE PAPER: UMTS/HSPA to LTE Migration

Disclaimer

The information contained herein is for information purposes only and is intended only to outline Motorola’s

presently anticipated general technology direction. The information in the roadmap is not a commitment or an

obligation to deliver any product, product features or software functionality and Motorola reserves the right to

make changes to the content, release and timing of any product, product features or software release. Prices

for any future product or software included herein will be separately negotiated when and if such product or

software becomes available.

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References

[1] The drivers to LTE, Motorola

[2] Long Term Evolution (LTE): Roadmap, Motorola

[3] Long Term Evolution (LTE), Motorola

[4] Long Term Evolution (LTE): A Technical Overview, Motorola

[5] Long Term Evolution (LTE): Air Interface, Motorola

[6] Long Term Evolution (LTE): Spectrum Analysis, Motorola

[7] LTE Upgrade Strategy

Contents

References ............................................................................................................ 3

Abstract ................................................................................................................ 4

A Dynamic Industry and Technology Evolution ................................................ 5

LTE Performance ...............................................................................................7

UMTS " LTE Network Architecture Evolution ..................................................9

Determine the Business Case for LTE ............................................................. 10

Subscriber Device Availability .......................................................................... 11

Deployment Considerations ............................................................................. 12

Seamlessly Connected Network ....................................................................12

Spectrum Implications ...................................................................................12

Maximize Existing Assets ...............................................................................12

UMTS to LTE Upgrade Strategy ....................................................................... 13

UMTS/LTE Architecture .................................................................................13

Functional Elements .......................................................................................13

UMTS / HSPA RAN Site Upgrade to LTE ........................................................14

Backhaul Site Upgrade to LTE .........................................................................15

LTE Voice .........................................................................................................16

LTE Video ........................................................................................................16

Conclusion .......................................................................................................... 17

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Abstract

As mobile data traffic increases exponentially and ARPU falls almost as rapidly, network operators in virtually every market are coming to terms with the need to change the way they deliver services. Preparing the network to meet the growing subscriber hunger for bandwidth demands a strategic and focused approach; only by making careful, well-planned choices in next generation technology will today’s operators survive in an increasingly competitive market.

LTE is the latest technology for 3GPP standards group, one that promises to deliver more throughputs and reduced latency while also reducing the cost of delivering the services subscribers demand. LTE deployment decisions today are driven by performance of today’s voice centric networks, regulated licensed spectrum, competition, subscriber applications and, of course, CAPEX budgets.

This document provides insight into an approach operators can apply now, with their existing networks, to get to LTE faster and more cost effectively. Motorola can offer a clear, direct transition path to LTE that makes use of the existing network coverage with seamless hand-over between HSPA and LTE. UMTS/HSPA to LTE migration is an option that allows operators to maximize the life and value of their existing assets while also achieving a truly 4G network.

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A Dynamic Industry and Technology Evolution

Wireless data services are following a growth curve similar to that of wire-line data as the performance and usability of mobile handsets has improved, 3G dongles laptops get introduced to the networks, and new wireless data services are rolled out. Higher data rates, flat rate tariff and continually improving coverage are expected to open up the mass market to wireless data services and drive demand for more rich multimedia content such as video. The number of subscribers, as well as usage rates, has grown considerably, and carriers have been upgrading their networks with 3.5G technologies in order to deploy both high-quality voice services and introduce mobile data services as shown in Figure 1. Service providers and equipment vendors are driving innovations and the latest wireless technologies are improving the efficiency of spectrum used – getting more capacity out of a given spectral bandwidth.

Figure 1 Global Mobile Market Share

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The 3GPP market is currently served by two technology lines: GSM (with GPRS, EDGE and Evolved EDGE) and UMTS (with HSDPA, HSUPA and HSPA+) and market share for both technologies continues to grow. The evolution and key technical aspects of these technologies are summarized below:

GSM A voice-centric FDD TDM based mobile architecture using an 8-timeslot 200 kHz carrier structure.

GPRS

Introduces a packet overlay to GSM. GSM air-interface timeslots carry shared packet data channels. GPRS added to the existing GSM RAN equipment via the PCU and a standardized Gb interface using frame-relay. Separate packet core network from CS, with optional coordination of mobility between the CS and PS domains.

EDGE High-speed enhancement to GPRS timeslots.

E-EDGE Proposed higher-speed enhancement to EDGE.

UMTS (R.99)

New network technology based on a FDD wideband-CDMA on a 5 MHz carrier. Separate network to GSM, with efficient handover between GSM and UMTS. Supports CS and PS services via dynamic dedicated channels to each terminal. Core network equipment may be an upgrade from GSM. Uses ATM and now IP transmission. The split of responsibilities between RAN and core at the Iu interface is different to GSM’s A/Gb interface.

HSDPA (R.5) / HSUPA (R.6)

(HSPA)

Adds new high-speed shared packet channels to the existing R99 UMTS system, and works within the R99 frequencies. Shared channels do not use soft-handover, and air-interface management functions for these channels moved from RNC to NodeB.

HSPA+ (R.7) Enhancement of HSDPA/HSUPA to exploit available radio technologies as well as the option of ‘flattening’ the existing complex architecture.

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The recent increase of mobile data usage and emergence of new applications such as MMOG (Multimedia Online Gaming), Mobile TV, Web 2.0 and Streaming Video have motivated the 3rd Generation Partnership Project (3GPP) to work on the next generation of wireless technology called Long-Term Evolution (LTE). LTE is the latest mobile network technology standard in the technology group that created the GSM/EDGE and UMTS/HSxPA standards that now account for over 89% of all mobile subscribers worldwide. LTE will ensure 3GPP’s competitive edge over other cellular and mobile broadband technologies; however, it does not preclude the use of LTE in conjunction with other wireless technologies (e.g. 3GPP2 and non-3GPP technologies such as WiFi). LTE is the next major step in mobile radio communications, and has been introduced in 3rd Generation Partnership Project (3GPP) Release 8.

LTE uses significantly different technologies both on the air interface and core network to bring maximum spectral efficiency and bring the network close to the world of IP; LTE uses Orthogonal Frequency Division Multiplexing (OFDM) as its radio access technology, together with advanced antenna technologies. The Evolved Packet Core (EPC) brings a flat IP architecture to support the LTE radio air interface and allow interconnection and hand over to legacy technologies.

LTE PerformanceThe LTE air interface has been designed to maximize and provide a consistent user experience across the whole cell. While LTE boasts peak data rate of over 170Mbps for 2x2MIMO configuration in a 20MHz channel (in Frequency Division Duplex mode). Even the more realistic sector throughput figures show a 3 to 4 fold improvement compared to HSPA Release 6 and 2.5x improvement compared to HSPA+ Release 8 in the same 5MHz channels as shown in the below figure 2 below. With the added advantage of larger channels size, LTE can provide a 10x fold improvement compared to the latest HSPA+ incarnation (3.7Mbps vs 33.4Mbps).

Figure 2. Sector throughput performance across different channel bandwidth – NGMN Case 3 scenarios

These capacity improvements are key to achieving the efficiencies necessary to reach the mass market and the lower cost per bit envisaged for LTE. Figure 3 below shows how LTE out performs previous technologies, providing a more uniform user experience across the whole cell.

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Figure 3. NGMN Case 3 constant footprint performance with HSPA @ 2.1GHz and LTE @ 2.6GHz. Same tower height, path loss and in building penetration as well as the same power density

HSPA+ release 7 and 8 radio improvements uses 64QAM and MIMO, and in consequence places emphasis on peak rate in the center of the cell, hence sector throughput improvement is only found in the region of 10-20% of the total cell coverage area. CDMA based technologies, such as HSPA, also experience cell shrinkage or “breathing” issues. This happens because all signals share a single carrier, so an increase in the number of subscribers on the network causes the interference to increase, leading to a shorter range to deliver the same data rate, ultimately resulting in a decrease of the effective cell radius.

LTE other performance features, which provide a number of capacity improvements include:

• Multiple antenna techniques to increase overall data rate.

• Better multi-path signal handling capability than CDMA technologies

• No intra-cell interference, as the sub-carriers are for a single subscriber in a time slot.

• Enhanced interference cancellation is better for reduced inter-cell interference.

• Mitigation of the cell shrinkage vs. loading phenomena of CDMA technologies.

• Lowered and more efficient control overhead.

• Frequency selective scheduling for additional flexibility and efficiency.

The spectral efficiency and capacity comparisons are summarized in Table 1 below.

Table 1: Spectral Efficiency and Capacity Comparisons 7

METRICPer Carrier

GSM Voice1 EDGE Data2 Rel 99 UMTS HSDPA6 HSPA+5 LTE Downlink3

Spectral Efficiency 0.04 bit/s/Hz 0.45 bit/s/Hz 0.2 bit/s/Hz 0.45 bit/s/Hz 0.74 bit/s/Hz 1.57 bit/s/Hz

Peak Data Rate 13 kbit/s -200 kbit/s -2 Mbit/s -14 Mbit/s 42 Mbit/s 170 Mbit/s

Sector Capacity 4 -100 kbit/s -270 kbit/s -1 Mbit/s -2.25M bit/s -3.7M bit/s 31.4 Mbit/s

No. of Transceivers/Cell to deliver thesame data capacity

111 111 30 14 8 1

Note: 1 4 x 12 repeat hard blocked; 2 1x3 soft Blocked; 3 20MHz carrier 2x2 MIMO; 4higher performance can be obtained depending on scenarios and techniques applied; 5 2 x 2 MIMO; 6 1 x 1; 7 Full Buffer Traffic

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UMTS " LTE Network Architecture Evolution

Figure 4 UMTS->LTE Architecture Evolution

In addition to LTE radio technology evolution, 3GPP has defined an IP-based, flat network architecture with much of RNC functionality now moved to the eNodeB and the remaining functions in the MME and Serving GW as shown in Figure 4. This architecture is defined as part of the System Architecture Evolution (SAE) effort. The LTE–SAE architecture and concepts have been designed for efficient support of mass-market usage of any IP-based service. By splitting control and the bearer plane, it allows for much more efficient scaling to better and more cost effectively support the growth in data usage per subscribers already experienced today on 3G networks today. It allows the operator to lower backhaul traffic by bringing the user plane node (GW) closer to the pool of Node-B . This architecture of optimized signaling and data processing, simplified operators and smooth cost efficient deployment different from existing GSM/WCDMA core networks but still allows for interconnections to legacy 3GPP technologies via the Serving Gateway and non-3GPP technologies via the PDN-GW to ensure inter-technology hand over, roaming, and to cater for a common billing and application layer.

UMTS

PHY(Transceiver)

Ciphering

RLC

MAC

HeaderCompression

Radio BearerControl

Radio AdmissionControl

DynamicResourceScheduler

Inter-cellRRM

Idle ModeLocation Mgmt

MobilityAnchoring

Authentication

Idle ModeLocation Mgmt

MobilityAnchoring

MobilityAnchoring

IP AddressAllocation

GGSN

SGSN

RNC

Node B

Connected modeMobility Mgmt

UMTS bearercontrol

Flow-based chargingIP flow to bearermapping

HSDPA

PHY(Transceiver)

Ciphering

RLC

MAC

HeaderCompression

Radio BearerControl

Radio AdmissionControl

DynamicResourceScheduler

Inter-cellRRM

Idle ModeLocation Mgmt

MobilityAnchoring

Authentication

Idle ModeLocation Mgmt

MobilityAnchoring

MobilityAnchoring

IP AddressAllocation

GGSN

SGSN

RNC

Node B

Connected modeMobility Mgmt

IP flow to bearermapping

UMTS bearercontrol

Flow-based charging

HSDPA

PHY(Transceiver)

Ciphering

RLC

MAC

HeaderCompression

Radio BearerControl

Radio AdmissionControl

DynamicResourceScheduler

Inter-cellRRM

Idle ModeLocation Mgmt

MobilityAnchoring

Authentication

Idle ModeLocation Mgmt

MobilityAnchoring

MobilityAnchoring

IP AddressAllocation

GGSN

SGSN

RNC

Node B

Connected modeMobility Mgmt

IP flow to bearermapping

UMTS bearercontrol

Flow-based charging

PHY(Transceiver)

Ciphering

RLC

MAC

HeaderCompression

Radio BearerControl

Radio AdmissionControl

DynamicResourceScheduler

Inter-cellRRM

Idle ModeLocation Mgmt

MobilityAnchoring

Authentication

Idle ModeLocation Mgmt

MobilityAnchoring

MobilityAnchoring

IP AddressAllocation

GGSN

SGSN

RNC

Node B

Connected modeMobility Mgmt

IP flow to bearermapping

UMTS bearercontrol

Flow-based charging

PHY(Transceiver)

Ciphering

RLC

MAC

HeaderCompression

Radio BearerControl

Radio AdmissionControl

DynamicResourceScheduler

Inter-cellRRM

Authentication

Idle ModeLocation Mgmt

MobilityAnchoring

MobilityAnchoring IP Address

Allocation

Serving-GW

E Node B

PDN-GW

MME

SAE/LTE

Connected modeMobility Mgmt

IP flow to bearermapping SAE bearer

control

Flow-based charging

PHY(Transceiver)

Ciphering

RLC

MAC

HeaderCompression

Radio BearerControl

Radio AdmissionControl

DynamicResourceScheduler

Inter-cellRRM

Authentication

Idle ModeLocation Mgmt

MobilityAnchoring

MobilityAnchoring IP Address

Allocation

Serving-GW

E Node B

PDN-GW

MME

SAE/LTE

Connected modeMobility Mgmt

IP flow to bearermapping SAE bearer

control

Flow-based charging

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Determine the Business Case for LTE

The current wireless broadband uptake in developed markets is fueled by the convergence of consumer desire for both mobile communication and broadband internet access. The growing traffic placed on the 3.5G networks is bringing significant network congestion in the urban areas and many operators are reporting that a significant portion of their cell sites in urban areas are already running at over capacity despite having enabled their all their UMTS carriers. This capacity crunch is leading many operators to deploy LTE to meet the needs of the mass market wireless broadband and allow for bandwidth-hungry applications such as video streaming to be supported cost effectively with the equivalent or better user experience.

The principle enablers of this broadband uptake are:

1. Widespread deployment of 3.5G networks.2. Multimedia Capable Smartphone (i.e., iPhone genre)3. Connected Laptop PC with USB dongles 4. Attractive flat rate and tiered tariffs, as low as $10 month to a handset5. Internet video streaming services

Figure 5 shows an example of a city with a population of 8 Million and an operator with 2 Million subscribers, who are moving from predominantly 2G mobiles to 3.5G wireless broadband as shown in 5. Although there are many variations to consider, detailed analysis and business modeling indicates that 3.5G technology can support this market quite well if typical data consumption is under 1 GByte/month/subscriber (Figure 5) beyond which the cost involved in supporting this data traffic on HSPA will make the case for LTE very attractive.

Figure 5 Real life HSPA operator metropolitan example

In effect, once the operator has deployed all of his 2-3 x 5MHz UMTS carriers the operator is faced with the need to provide additional capacity and can only continue doing so by adding more cells sites or by means of an LTE network overlay. In this case, Figure 6 shows the addition of an LTE network allows the capacity to be addressed without the need to find and deploy additional cell sites (Figure 6: Leftmost graphic). The operator initially promotes and LTE for the heaviest data users, the laptop subscribers, and relieves the congestion on the 3.5G network for the handset subscribers (Figure 4: Right most graphic).

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Figure 6. Real life HSPA operator metropolitan example – 3GB/month/subscriber in 2011 and 45% mobile broadband subscribers. Left: Cell site numbers to support data growth. Right: Subscriber/device migration strategy

In this example, we see that by adopting the high capacity LTE in addition to a HSPA network and leveraging existing sites for LTE deployment, the follow benefits are achieved

1. Deliver mass market wireless broadband that meets the growth in mobile data usage2. Minimize the proliferation of cell sites resulting in lower OPEX and CAPEX that would have been

required for a HSPA-only network3. Enhance consumer experience by relieving congestion throughout the whole cell site4. Leverage High Performance LTE for early adopters (e.g. laptop users)

Subscriber Device Availability

Consumer device availability is generally dictated by timing of mobile chipsets. LTE mobile chipset samples are expected to start shipping from the middle of 2009, which could deliver early USB dongles in Q1-2010 meaning early LTE operators can start off-loading heavy laptop/netbook users from early 2010. First mobile phones are expected towards the end of 2010 and mass market handsets may appear mid to late 2011. A general view of the LTE eco system development is shown below.

Figure 7. LTE ecosystem roadmap

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Deployment Considerations

Seamlessly Connected NetworkA seamlessly connected network enhances the user experience, protects investments, adds flexibility, and increases efficiency.

The 4th generation of wireless systems will provide users with easy access to voice, data and multimedia. The success lies in the evolution of GSM/UMTS and LTE networks where all 3 networks appear to the subscribers as a single seamless network providing invisible roaming from one technology to the other and providing near ubiquitous coverage. The migration from GSM/UMTS to LTE involves a major change in networking technology moving fundamentally from a circuit switched network to all-IP technologies, which involve new approach in planning a network and new technical challenges such as E2E QoS, Backhaul, etc. Motorola has extensive experience in deployment of IP based technologies like CDMA EV-DO and WiMAX. We can bring that expertise in network planning, deployment, optimizations and associated managed services to bear on the EUTRAN/EPC networks.

Combining and interworking of LTE with legacy GSM/UMTS technologies will help provide full coverage for voice, data, and multimedia services. In effect, because LTE can hand off from and to GSM/UMTS complete LTE coverage is not required from day one to provide services in every geographic location. When users who require both voice and data services move out of the LTE coverage area, the network automatically switches from LTE to the ubiquitous GSM/UMTS network.

Spectrum Implications UMTS needs to be deployed on a full 5 MHz of spectrum, with the vast majority of UMTS/HSPA deployed today utilizing the 2.1GHz UMTS/HSPA band. In comparison LTE provides initial deployment scalability as it can be deployed in any ITU recognized spare spectrum, having the ability to be deployed in bandwidths between 1.4 MHz and 20MHz, and subsequently grown as additional bandwidth becomes available. The spectral efficiency of LTE only starts to drop a little for spectrum below 5MHz (10-15%) but still provide significant capacity with these lower spectrum bandwidths.

LTE spectrum bandwidth flexibility means that some operators can consider re-farming unused GSM spectrum for LTE deployment as LTE becomes commercially available. Still, it looks like the most likely bands for LTE in the 3GPP markets will be new virgin spectrum bands. For example, as much as 190 MHz of IMT2000 2.6 GHz expansion spectrums is being auctioned in EMEA, APAC and LAC. It is likely that LTE will be deployed in this band as it offers a unique opportunity for the deployment of LTE in maximum spectrum bandwidth by providing channels of up to 20 MHz hence is a perfect “capacity” band.

In addition, new digital dividend spectrum (800MHz band) is being released by the switch off of analog terrestrial TV services in many countries, and will be auctioned in EMEA, APAC and LAC. Although not as wide (70MHz in total), the 800MHz is nonetheless a very attractive band for the wider coverage and better in-building penetration it provides compared to the higher frequencies.

Maximize Existing AssetsSite acquisition costs, ancillaries, new backhaul links, and management costs have been recognized as some of the key issues driving the business case of deploying LTE as LTE can add significant capacity leveraging existing site grid and installed ancillaries. Operators can leverage existing investments by reusing the existing equipment for their LTE networks. Shared resources, including common transport (if adequate), site re-use and open interfaces to equipment such as existing OSS/ BSS systems can offer a cost efficient network solution. Both capital expenditure (CapEx) and operating expenditure (OpEx) savings can be realized when evolving from an existing network to a seamless LTE one.

CapEx

The radio access network is one of the most expensive parts of a wireless network and the cost of ancillaries and site acquisition can be as high as 10x the cost of the BTS, hence re-using existing site grid offers significant opportunity for potential CapEx savings. Coexistence of legacy and LTE technologies in the

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same site provides an opportunity to share expensive backhaul facilities and leverage already depreciated ancillaries by simply adding a compact LTE EUTRAN. Co-location of Motorola equipment on a site increases the potential for savings thanks to Motorola’s LTE solutions, which are designed for flexible deployment.

OpEx

An operator OpEx is directly proportional to the number of sites, leveraging the existing site grid for LTE and limiting the number of new sites has significant benefits and will positively impact OpEx in the long term. In addition, LTE Self Organizing Network (SON) features, allowing automation of previously manual tasks linked to planning, deployment, optimization and operation will maximize the O&M OPEX reduction of LTE. A common customer care system and a single billing system can also lead to substantial OPEX savings, both in terms of personnel and training costs.

UMTS to LTE Upgrade Strategy

UMTS/LTE Architecture

Figure 8: UMTS/LTE Architecture

Functional ElementsA brief description of the functional elements that make up the EUTRAN/EPC is provided below:

• The eNodeB (eNB) encompasses the bottom layers of the radio link between the user equipment (UE) and the network. It performs many functions including radio resource management, admission control, scheduling, enforcement of negotiated UL QoS, cell information broadcast, ciphering/deciphering of user and control plane data, and compression/decompression of DL/UL user plane packet headers.

IP NetworkIP Network

RNCBSC

NodeBBTS

eNodeB

PDN GW

Other Access Technologies

Other Access Technologies

MME

PCRF

HSS SPR

Serving GW

SGSNGGSN

2G 3G

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• The Mobility Management Entity (MME) is the key control-node for the LTE access-network. It is responsible for idle mode UE tracking and paging procedure including retransmissions. It terminates Non-Access Stratum (NAS) signaling used for bearer activation/deactivation processes, user authentication (by interacting with the HSS), and generation and allocation of temporary identities to UEs. Lawful interception of signaling is also supported by the MME.

• The Serving Gateway (SGW) routes and forwards user data packets, while also acting as the mobility anchor for the user plane during inter-eNB handovers and as the anchor for mobility between LTE and other 3GPP technologies. It also performs replication of the user traffic in case of lawful interception.

• The Packet Data Network Gateway (PDN GW) The PDN GW provides connectivity between the UE and external packet data networks (PDN) by being the point of exit and entry of traffic for the UE. A UE may have simultaneous connectivity with more than one PDN GW for accessing multiple PDNs. The PDN GW performs policy enforcement, packet filtering for each user, charging support, lawful Interception and packet screening. Another key role of the PDN GW is to act as the anchor for mobility between 3GPP and non-3GPP technologies such as WiFi and 3GPP2 (CDMA 1X and EvDO).

UMTS / HSPA RAN Site Upgrade to LTEThe vast majority of legacy UMTS equipment currently deployed in the field is not LTE capable and even the latest Multi-technology BTS will require new hardware (baseband and radios) to run an LTE network as the underlying enabling technologies behind LTE (OFDM and All IP Flat Core Architecture), are fundamentally different from GSM and UMTS. Also, the very high throughput of LTE means that the baseband processing requirement is significantly higher than that of even the latest HSPA+ incarnation

HSPA networks will not be switched off when LTE is launched and because LTE will most likely be deployed initially in new spectrum bands (2600 or/and 800MHz), operators will have to overlay their existing HSPA equipment with new baseband, new radios and other ancillary elements.

Based on analysis using Motorola’s extensive expertise in OFDM and MIMO, a dedicated OFDM platform capable of supporting LTE maximum capabilities will provides the best performance and maximum OPEX reduction for LTE deployment and operations. For that reason and considering LTE is the latest technology that will carry an operator’s traffic for the long term future, it is in the operators’ best interest to deploy a dedicated LTE RAN network as the best LTE solution possible.

GSM and UMTS networks are the still active networks today, so to de-risk the installation of LTE and ensure no disruption of existing services, an LTE overlay solution has the benefit of limiting the risk of disruption of legacy technologies in the early phase of LTE deployment.

Motorola has designed the LTE BCU and LTE Radios to minimize OPEX and CAPEX, thus ensuring a smooth and unobtrusive overlay in existing sites. The compact indoor 19” baseband unit that can be integrated in any 19” rack space, or even fitted on an internal wall. If the operator has ran out of space in their existing shelter, Motorola can also offer a compact outdoor versions of the same baseband solution that can be fitted on outside walls, roofs or directly attached to the bottom of the cell tower.

The LTE radio transceivers, which can be mounted either locally or remotely to the LTE BCU, are connected back to the LTE BCU via a CPRI like fiber interface, with their RF outputs duplexed onto the same RF feeder cables as the UMTS Node B. This allows the operator to re-use much of the ancillary equipment previously purchased at the Node B whilst being able to offer both UMTS and LTE services.

In general, whenever technically and commercially feasible, antennas should be shared between the existing UMTS equipment and the new LTE system. The goal is to reduce the operator OPEX associated with running multiple technologies at the same site. Since each deployment scenario and requirements are different, Motorola will work with individual operators to address their specific deployment needs.

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Backhaul Site Upgrade to LTEBackhaul consideration for LTE E-UTRAN deployment is also critical. A typical LTE site (20 MHz, 3 Sectors, 2x2 MIMO) may present a Busy Hour (BH) backhaul load of nearly 100 Mbps average throughput, with individual peaks well above that. This amount of bandwidth in the I/O will most likely require controller and backhaul upgrades. Today’s E1 backhaul – 2Mbps – is very unsuited for 4G technologies so a significant upgrade on the backhaul network will also be required. Wireless high speed IP microwave backhaul, fibre or even DOCSIS 3.0 can provide a very cost effective and high speed solution for backhauling LTE sites.

Motorola has designed and deployed backhaul solutions for many high speed commercial wireless broadband OFDM networks and has the solutions and the expertise to ensure LTE network capability is not throttled by backhaul limitations.

Migration to EPC (Evolved Packet Core)

Motorola offers the flexible solutions to introduce the EPC architecture for the next generation mobile broadband network. Motorola EPC (EPS Core) is based on the Wireless Broadband Gateway (WBG) and Wireless Broadband Controller (MME). For some deployment scenarios, Motorola recommend the overlay approach that can minimise the operational impact on the existing networks at the cost of additional elements installation. For other deployment scenarios where the operators are willing to save the physical space and leverage the existing sites, Motorola’s new LTE ready platforms (WBG) can support GSM/UMTS and LTE simultaneously and have higher performance and capacity than most installed GSN platforms today. The WBG platform is software upgradeable from GSM/UMTS to LTE without new platform nor cards and is available today. Motorola’s SGSN/GGSN platform (ST40) can be leveraged to support the Serving-GW and PDN-GW functionality for the LTE Core Network. The Wireless Broadband Gateway platform supports the following functions in either distributed or centralized configuration:

• SGSN

• GGSN

• Serving-GW

• PDN-GW

This architecture provides minimum incremental cost for an initial low capacity LTE system and a better long term investment than expanding an existing or new GSN system. Over time, all Packet traffic can be migrated to this new high performance core network.

The Motorola’s WBC700 EPC implementation separates the control and bearer plane via separate physical platforms for the MME and SGW/PDN-GW functions. This separation of platforms provides a number of benefits to the operators, including the following:

• Allows independently targeting of capacity and equipment growth to the control or bearer plane functions.

• Allows platform hardware matched to function, i.e. use of ATCA for control plane and IP routing platform for bearer plane.

The Motorola WBC700 MME function is based on Motorola’s field proven WiMAX CAP-C and EV-DO IP-BSC-DO platforms. This has a signalling optimized architecture using an ATCA platform that allows balancing of performance and cost by providing special packet or crypto processing. It has ~2x capacity and ~0.5x cost of a bearer box performing MME functionality.

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LTE VoiceThe use of Single Radio – Voice Call Continuity (SR-VCC) capabilities inside the Motorola EPC will assist the IMS core in providing mobility of multi-media sessions, especially when one or more are legacy circuit services. This technical approach represents the long-term end goal of LTE. Alternately, Circuit Services – Fallback (CS-Fallback) and Voice over LTE via Generic Access (VoLGA) provide bridge alternatives to introduce legacy services with mobility in near-term LTE deployments. Each technical approach leverages the legacy 2G/3G networks in different ways.

CS-Fallback is a 3GPP R8 standard that reuses the entire 2G/3G Core and RAN while subscriber is on LTE. It requires a dual-mode device. The user is registered on both the LTE and the 2G/3G networks. All data sessions are established on LTE, Short Messages Services (SMS) are delivered as tunneled data sessions and for voice legacy services, the dual-mode device will switch off LTE frequency to 2G/3G frequency to make or take the voice call.

The VoLGA Forum is a consortium of vendors and a key driving operator (T-Mobile) who are defining common specifications for this technical approach. VoLGA leverages only the 2G/3G Core (e.g. MSC or MSC Server) via extensions to Generic Access. There is an interworking function between LTE EPC and 2G/3G Core that allows LTE devices to access legacy services via LTE access (i.e. dual-mode devices not needed, 2G/3G RAN not needed). All legacy services, like SMS and voice, both bearer and signaling, are just data sessions through the LTE EPC. The interworking function presents these data sessions to the 2G/3G Core in standard 3GPP legacy interfaces.

Motorola plans to support the capabilities in our LTE EPC and EUTRAN to accommodate all three technical approaches. For fixed LTE deployments (e.g. no mobility nor roaming required), VoLGA can work today with existing 3GPP LTE standards (e.g. the Sv interface is NOT needed). Please contact your motorola representative for more information on voice services for LTE.

LTE VideoLTE capacity and lower cost per bit allows for high quality video streaming on any type of mobile devices. Mobile operators with fixed line broadband networks that are already offering IPTV like services will also be able to leverage these assets on LTE. Rich media solutions connected to the LTE core network will give the operators the ability to converge broadcasting, video on demand, innovative applications and advertisements solutions into their LTE service and thus give them the opportunity to monetize their LTE network with innovative applications such as Quad-play service and media mobility between access technologies and devices.

17 WHITE PAPER: UMTS/HSPA to LTE Migration

Conclusion

It is expected that many traditional UMTS / HSPA service providers may want to take advantage of the benefits of LTE and choose to migrate along the 3GPP standards path. It is not necessary for UMTS/HSPA service providers to go to HSPA+ in order to deploy LTE. Further, many existing UMTS deployments will need significant hardware upgrades to support 3GPP Release 7 and 8 HSPA+ functionalities. Motorola can offer a direct, well planned transition path from HSPA to LTE that leverages the operators existing infrastructure and site grid and configuration.

Motorola’s LTE solution presents a straight-forward evolution to the world of mobile broadband for the 3GPP service provider. With the envisaged throughput and latency targets complimented by and emphasis on simplicity, spectrum flexibility, added capacity and lower cost per bit, LTE is destined to provide a greatly improved user experience, and to deliver new revenue generating mobile services that will excite users and help operators drive competitive advantage and benefit their mobile broadband services profitability.

To realize these goals Motorola is leveraging its extensive expertise in mobile broadband innovation, including OFDM technologies (WiMAX, Expedience), cellular networking (GSM, UMTS/HSPA, EV-DO), collapsed IP architecture, standards development, video leadership, and comprehensive services to deliver a best-in-class award winning LTE solutions. Leveraging the benefits of Motorola’s mobile broadband experience and proven expertise in OFDM network deployments, Motorola’s LTE end-to-end solution will provide a seamless and flexible path to LTE with a high degree of future proofing for the service provider. Following this path, Motorola’s 3GPP customers will be well positioned to provide the world’s most compelling mobile broadband services and applications.

For more information on Motorola LTE and HSPA to LTE migration, please talk to your Motorola representative.

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