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4G Technologies(Wimax

Mobile, LTE, CDMA450/800)

Irinel OLARIU - Voice&Data Offers Project Manager, TD/NET/CT&IP Network Group

April 14th 2010, presentation for Orange Telecom University

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2 Implementing various QoS mechanisms Orange Romania - France Telecom Group

Agenda

1. Introduction to (MBWA) Networks

2. WIMAX Mobile

3. Introduction to LTE

4. Introduction to CDMA 450/800

5 Conclusions

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1. Introduction to Mobile

Broadband Wireless Access

(MBWA) Networks

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The choice of mobile network technology to use is becoming more difficult.

In developed European markets the choice has been, and continues to be

driven to a large extent, by existing assets and the 3GPP roadmap.

However in other markets things are not so straightforward and a host of

considerations are required including regulatory and spectrum restrictions,

degree of mobility, coverage and capacity performance.

Several technologies for mobile data broadband emerged in the last few

years such as: evolutions of HSPA, LTE, WiMAX, CDMA450/800, FlarionFlash-OFDM, IP Wireless TD-CDMA etc. They all have a strong ability to

manage bursty traffic (small packets) without undue real time constraints,

and recent optimization allows real time services offers (voice and video)

with acceptable quality of service.

Some of the technologies described in earlier version of this document didnot get enough industry support and it seems now clear that they wont get

massively deployed. This is the case for Flarion Flash-OFDM and IP

Wireless solutions for example.

Introduction to (MBWA) Networks

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Introduction to (MBWA) Networks(cont) With regard to latency, 3G has closed the apparent gap with WiMAX to a

very large extent with R6 HSPA. Furthermore, HSPA+ Rel7 will deliver

improvements that should allow its performance to match or exceed other

technologies and provide an excellent wide-area underlay to potential LTEnetworks. The targets for LTE should exceed those of the other systems

and approach the user perception levels associated with DSL.

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Introduction to (MBWA) Networks(cont)

All technologies are not at the same level of maturity, making

it difficult sometimes to compare. This is why the roadmaps

and timing are described, and when applicable, it is specified

whether the figures are resulting from simulation, trials or

simply claimed by the suppliers.

This report covers the following technologies: HSPA, LTE,

Fixed and Mobile WiMAX, and CDMA 450/800. It is structured as follows:

A technology by technology description covering essential

aspects, coverage, capacity, trial results and equipment

roadmaps.

A comparison of LTE versus mobile WIMAX performance

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2. WIMAX Mobile

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WIMAX Mobile

Many technical options exist in WiMAX systems: the standard on which it is based

(802.16d or 802.16e), the frequency in which it operates, the channels mode

(TDD, FDD) and the channel bandwidth (3.5MHz, 5 MHz, 7 MHz, 10 MHz).

Therefore it is important to specify the associated options when we speak about

WiMAX performance. Fixed WiMAX (802.16d) and Mobile WiMAX (802.16e) are

not compatible. This means that a 16d network can NOT be upgraded in 16e (all

base stations and terminals need to be replaced and the architecture is also

different.

Fixed WiMAX (802.16-2004 or 16d) is mainly targeting Fixed and Portable applications,where the CPE is either a rooftop (often directional) outdoor antenna or an indoor

desktop modem.

Mobile WiMAX (802.16e) is targeting nomadic and mobile applications using

datacards/PC terminals, but could be also deployed for fixed usage with fixed

outdoor/indoor CPEs.

Technology trials have been conducted for both technologies:

WiMAX 16d with Alvarion equipments in 2005 in LA Salvetat (France) in FDD at 3.5 GHz

and 3.5 MHz channel bandwidth, using outdoor CPE with directive antenna, which is

typical of a Fixed WiMAX deployment.

WiMAX 16e in 2007 in Poland with Samsung equipments, in TDD at 3.5GHz and 10MHz

channel bandwidth, using PMCIA cards.

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WIMAX Mobile

Coverage

802.16e has been developed mainly for Nomadic and Mobile usage.Therefore, PCMCIA cards and laptops are the typical target CPE for

this system. Such CPE have very low antenna gain. Furthermore,

the envisaged spectrum for Mobile WiMAX (2.5 GHz or 3.5 GHz) is

not very favourable from a radio propagation point of view.

Therefore, many features will be implemented (mostly in Wave 2

products) to improve the link budget such as:

UL sub channelling, turbo codes, repetition, and AAS.

With these enhanced features implemented, we can consider that the

coverage of WiMAX and 3G are similar, as long as they are deployed

in equivalent spectrum bands, i.e HSPA @ 2.1Ghz and WiMAX @

2.3 or 2.5 Ghz have similar cell coverage. At 3.5GHz, the radio

propagation is worse and WiMAX coverage is significantly reduced.

WiMAX 16e coverage was found to be uplink limited due to terminal

power limitation.

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Mobile WiMAX products will work in TDD mode in either 5

MHz, 7MHz or 10 MHz channel bandwidths, and spectral

efficiency is equivalent for each bandwidth:

WIMAX Mobile

Spectral efficiency is in the range of ( 9 Mbps/10MHz*2/3)/3=

0.45bit/s/Hz for Downlink and (3 Mbps/10MHz*1/3)/3= 0.3

bit/s/Hz for Uplink. Wave 2 features, such as MIMO should

improve the spectral efficiency, especially in noise limited

environments (indoor, micro cells). A trial of Wave 2 multi-user features was conducted in Samsung premises in Sept

2008. Sprint just opened a WiMAX network in the US with a

frequency re-use of 3.

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WIMAX Mobile

Latency

A RTT of around 100ms was measured in the Poland 16etrial in 2007, whichis significantly worse than the advertised

latencies for WiMAX (~50ms).

Mobility

Handover experience in mobility on the Poland trial wassurprisingly good given the basic nature of the procedure.

HO interruption time was stable:~77ms for intersector,~92ms

for inter-BS, and the session continuity was ensured with a

minimum impact on throughput.

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3.LONG TERM EVOLUTION(LTE)

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LONG TERM EVOLUTION (LTE) Introduction

LTE or Evolved Universal Terrestrial Radio Access (E-UTRA) is aimed at

evolving 3GPP radio access technology towards a high data rate, low

latency and packet optimised technology. The key targets for LTE regard

headline data rates, reduced latency, spectrum flexibility, reduced cost per

bit and ability to operate efficiently in an all-IP environment with no circuit-

switched domainmeaning VOIP for voice calls. Reduction of cost per bit

will be the main driver for LTE.

The air interface for LTE is OFDM downlink and SC-FDMA uplink. The

mobility management functions currently performed by the RNC are

devolved to the Node B for LTEie it has a Collapsed architecture. It

targets a flexible use of spectrum, with several bandwidths defined: 1.4 / 3

/ 5 / 10 / 15 and 20 MHz.

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LONG TERM EVOLUTION (LTE)

The LTE advanced antenna system will use adaptive MIMO(Multiple In Multiple Out) with a minimum of 2 antennas at

each end of the link (ie 2 antennas at the basestation and 2receive antennas at the terminal). The system will adaptbetween beam-forming and multi-stream transmission modesdepending on the propagation environment of the terminal.OFDM is inherently better suited to MIMO schemes thanWCDMA and this should enable LTE MIMO to generate

higher system gains than WCDMA with lower receivercomplexity.

Performance

LTE will be optimised for low mobility, but will also supporthigh speed mobility with tolerable performance degradation.

LTE standardization should be completed in March 2009, soperformance figures are currently based upon simulations.Initial test results from prototype equipments are availablefrom LSTI forum, and more results will be available from trialsin 2009-2010, which progressively will be based uponequipment adhering more and more closely to the evolvingstandard.

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LONG TERM EVOLUTION (LTE)

Coverage

The coverage of LTE will depend on the operating frequency. It

is currently foreseen that LTE will be deployed first at 2.6

GHz when available, then maybe in 1800 or 900 MHz when

re-farming GSM bands. Initial link budget analysis has shown

that coverage of LTE at 2.6 GHz could be equivalent as the

HSPA coverage as 2.1GHz, so the same sites can be re-

used. This topic still needs more internal study.

Latency

LTE has a reduced latency of 10 ms radio RTT and less than

20 ms end to end RTT in user plane and 100 ms in control

plane.

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4. CDMA 450/800

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CDMA 450/800

Introduction

CDMA450/800 are CDMA2000 systems deployed in the

450MHz and 800MHz band respectively, which includes thefamily of standards developed by 3GPP2 for the radiotechnologies: CDMA2000 1X (Rel.0 and Rev.A), EV-DO(Rel.0,Rev.A) and EV-DV (no commercial).

CDMA450/800 belongs to the 3GPP2 family of standards

and there is no provision for interworking with GSM orWCDMA. In terms of performance, CDMA2000 does nothave any strong advantage over UMTS or othertechnologies, but it is widely available at 450 Mhz. This bandoffer excellent radio propagation, which is why CDMA450 is agood option in some markets.

The bandwidth for CDMA2000 is very limited (1.25MHz) andso capacity is restricted. This makes CDMA450 onlyappropriate for low density coverage. If the traffic grows toomuch, the cells would have to be split to provide greatercapacity, thus negating one of the main advantages of

CDMA450.

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CDMA 450/800

Coverage

Sonatel CDMA450 deployment showed very large cell ranges. But it has to be

noted that very high gain antennas at both the BS and the terminal are used.High gain 450MHz antennas are typically twice the size of the equivalent gain

900MHz antenna. Therefore available space on the tower head-frame pluswind loading must be taken into consideration when planning a CDMA450site.

A 450MHz terminal with integrated antenna would likewise give poor

performance, whereas the FWA terminal equipment can use an externalantenna (twig or yagi) with superior gain. This is a reason why CDMA450lends itself to a fixed wireless application.

Sector & user throughput

Sonatel have deployed CDMA450 for rural fixed-wireless coverage usingtheir existing GSM site portfolio. The basic offering is CDMA 1X which gives153 kbps in the downlink and 38 kbps in the uplink. A smaller number ofsites have been upgraded to EVDO on a 2nd carrier which gives 2 Mbps inthe downlink and 153 kbps in the uplink.

Latency

Radio RTT was measured in a field trial in Tibet with Huawei equipmentsand was in average 250ms.

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5. Questions?

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