Driving Broadband Innovation in UAE

Dubai Metro: A CASE STUDY

Dr. Ayman Elnashar Director - Wireless Broadband EITC (du) UAE

Agenda

• du Broadband Portfolio

• Dubai Metro: A Case Study

• WiMAX Versus HSPA+ Evolution

du outdoor Mesh-WiFi

du Broadband Portfolio

du WiFi Hotspots

du Pre-WiMAX Point-to-Point & Point-to

-MultipointLinks

du WiMAX network for the Dubai Metro

du Fixed network Services

du UAE Nationwide Mobile Network

Mobile Broadband

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Du Broadband Wireless Portfolio Executive Summary •  Nationwide HSPA(+) Network •  WiMAX Technologies

  Mobile WiMAX (802.16e) as backhaul for Metro WiFi   Fixed WiMAX (802.16d) and Pre-WiMAX (Proprietary

OFDM technology) as an extension to fixed services and for very high bandwidth requirements in Remote Areas.

•  WiFi Technologies   Nationwide Indoor WiFi Hotspots   Dubai Metro WiFi

…  On-Board all trains …  Covering all stations (Redline + Greenline)

DUBAI METRO: A CASE STUDY

Award: The most innovative Mobility Project for 2009 by CISCO

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DUBAI METRO The Dubai Metro project consists of two lines, i.e., Red line track (52.1 km) and Green Line (17.6 km).

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DUBAI METRO: AN OVERVIEW

du IP Core Network

On-Board WiFi Controller

TRAIN

Stations

WiFi AP

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WHY WIMAX BACKHAULING

WiMAX Versus HSPA

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Cell Radius Comparison between WiMAX at 2.6 GHz and HSPA at 2.1GHz

•  Key Link Budget Parameters   HSxPA is mainly Downlink

Limited …  Meeting the 512Kbps at cell

edge is the main limiting factor

…  Absolute minimum HSDPA percentage power to guarantee this throughput for a “single” user is 28%.

  To leave room for more than one user to achieve this throughput at cell edge the following criteria is used in link budget:

…  Percentage Power for HSxPA = 35%

Comparable Cell Radius But HSxPA Cell Radius is sensitive to Loading as shown in

the next 2 slides

Effect of Loading on HSPA Cell Radius

Slide 11 | Broadband Wireless | January 2009

•  Cell Breathing Phenomena: Cell Radius shrinks as a function of loading   Even becomes Uplink limited under very high loading and theoretically

the cell radius goes to zero if uplink loading hit the 100%.

Supported 512Kbps users at cell Edge Vs. HSPA Cell Radius

Slide 12 | Broadband Wireless | January 2009

•  HSxPA:   2x5MHz carriers   Carrier 1:

…  30% R99 …  70% HSPA

  Carrier 2: …  100% HSPA

•  Cell Radius shrinks as a function of number of users at cell edge meeting the 512 Kbps Throughput   Only 6 users can achieve the throughput and the cell radius shrinks to 200 m only

•  WiMAX can serve 8 users (512 Kbps) at cell edge with a cell radius of 450 m (no cell shrink in WiMAX)

Slide 13 | Broadband Wireless | January 2009

Capacity Comparison per Cell WiMAX using 10 MHz Channel HSPA(+) using 2x5 MHz Carrier (10 MHz DL/10 MHz UL) i.e., 20MHz

0

2

4

6

8

10

12

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HSPA HSPA+ WiMAX

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13 13.44

4 4.6

4

Mbps

Average Throughput per Cell

Downlink

Uplink

On cell basis, the WiMAX cell spectrum efficiency (1.744) is almost double the spectrum efficiency of the HSPA+ cell (0.88).

Capacity Comparison per Site WiMAX using 3x10 MHz Channels (30 MHz) (30 MHz with 1/1/3 Frequency reuse) HSPA(+) using 2x5 MHz Carrier (20 MHz)

0

5

10

15

20

25

30

35

40

45

HSPA HSPA+ WiMAX

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39 40.32

12 13.8

12

Mbps

Average Throughput per Site

Downlink

Uplink

On the site basis, the spectrum efficiency of WiMAX equal 1.73 while the HSPA+ is 2.64 and for WiMAX it will be even less if we considered the guardband but

this could be equivalent to the noise floor rise in HSPA network

WiMAX Pros and Cons •  No cell breathing and therefore QOS can be guaranteed even at cell

edge. •  TDD spectrum is cheaper than FDD spectrum. •  The ease of implementing the state-of-the-art techniques like MIMO

and beamforming due to the Reciprocity of the RF propagation channels.

•  Wide scale of QOS levels compared to HSPA technology. •  Same cell radius at 2.6 GHz compared to HSPA at 2.1 GHz thanks to

MIMO and beamforming techniques. •  Flat architecture based on IP network and very high capacity ASN

-GW. This leads to low latency; typically 50 to 60 ms. •  WiMAX network would be cheaper than HSPA network. This is mainly

due to the need for 2/2/2 configuration of HSPA site to reach same capacity of 1/1/1 WIMAX site with 10MHz channel.

•  Upon solving the issue of spectrum efficiency, the WiMAX technology will be an ideal 4G technology.

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WiMAX Pros and Cons Cont…

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•  Since WiMAX is based on TDD then guardband between TDD & FDD is mandatory. Therefore, a network with 3x10MHz spectrum which deployed using 1/3/3 frequency reuse would need 5 to 10 MHz guradbands based on the vendor.

•  The difficulty in implementing the network using frequency reuse of one similar to CDMA based technology.

•  The above drawbacks has major impact on the spectrum efficiency. •  A feature called fractional frequency reuse is available with some

vendors but not really tested in major deployment. •  Strict synchronization is needed and also with adjacent TDD operator

to minimize or eliminate guardband requirement. •  Lack of dual mode handset which can support WiMAX along with 2G

/3G technologies. •  The difficulty in expanding indoor DAS system to support above 2.5

GHz band. Therefore, the only way is to swap the passive system with active system to support higher frequency.

•  Lack of real competition between the vendors due to the exit of major mobile vendors from the WiMAX market.

HSPA(+) Pros and Cons •  No need for guardband between adjacent operator and carrier leakage can

be tackled since CDMA-based systems is capable of mitigating interference. •  The introduction of many new features like 64QAM in DL, MC-HSPA(+) and

16QAM in the UL has significantly improved the HSPA networks capacity. •  Also, the introduction of new features like VOIP over HSPA and CS over

HSPA has increased the potential of HSPA in serving fixed customers due the noticeable voice capacity increase low CAPEX investment.

•  Better spectrum efficiency thanks to frequency reuse one and robust interference mitigation inherited from CDMA nature.

•  Wide availability of Smartphones and handsets.

•  Cell breathing reduce coverage probability and reduce throughput at cell edge.

•  Low QOS degrees and therefore HSPA networks suites the bursty traffic. •  High CAPEX investment due to the need for 2/2/2 configuration to increase

the network capacity. •  some important features like MIMO are not compatible (i.e., degrade the

performance) with legacy handset.

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Thank You

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