3. du Broadband Portfolio
Mobile Broadband
du Fixed network
Services
du WiMAX network
for the Dubai Metro
du UAE Nationwide
Mobile Network
du outdoor Mesh-WiFi
du Pre-WiMAX Point
-to-Point & Point-to
-MultipointLinks
du WiFi
Hotspots
3
4. 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)
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5. DUBAI METRO: A CASE STUDY
Award: The most innovative
Mobility Project for 2009 by CISCO
5
6. DUBAI METRO
The Dubai Metro project
consists of two lines,
i.e., Red line track (52.1
km) and Green Line
(17.6 km).
6
7. DUBAI METRO: AN OVERVIEW
TRAIN
WiFi AP
On-Board WiFi Controller
du IP Core
Network
Stations
7
10. 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:
Comparable Cell Radius … Percentage Power for HSxPA
But HSxPA Cell Radius is sensitive to Loading as shown in = 35%
the next 2 slides
11. Effect of Loading on HSPA Cell Radius
• 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%.
Slide 11 | Broadband Wireless | January 2009
12. Supported 512Kbps users at cell Edge Vs. HSPA Cell
Radius
• 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 12 | Broadband Wireless | January 2009
13. Capacity Comparison per Cell
WiMAX using 10 MHz Channel
HSPA(+) using 2x5 MHz Carrier (10 MHz DL/10 MHz UL) i.e., 20MHz
Average Throughput per Cell
13.44
14 13
12
10
8
8
Mbps Downlink
6 4.6
4 4
4
Uplink
2
0
HSPA HSPA+ WiMAX
On cell basis, the WiMAX cell spectrum efficiency (1.744) is almost double
theSlide 13 | Broadband Wireless | January 2009 of the HSPA+ cell (0.88).
spectrum efficiency
14. 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)
Average Throughput per Site
45 40.32
39
40
35
Downlink
30
24
Mbps 25
Uplink
20
13.8
15
12 12
10
5
0
HSPA HSPA+ WiMAX
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
15. 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.
15
16. WiMAX Pros and Cons Cont…
• 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.
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17. 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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