Engineering realities of radio spectrum for mobile broadband.

1. Spectrum
Engineering Realities
Peter Rysavy
http://www.rysavy.com
July 2012
1 Copyright 2012 Rysavy Research

2. U.S. Spectrum Crunch
Frequency Amount of Comments
Band Spectrum
700 MHz 70 MHz Ultra-High Frequency (UHF)
850 MHz 50 MHz Cellular
1.7/2.1 GHz 90 MHz Advanced Wireless Service (AWS)
1.9 GHz 120 MHz Personal Communications Service (PCS)
2.5 GHz 194 MHz Broadband Radio Service
(significantly less deployable)
600 MHz Up to 120 MHz Incentive auctions. Ten year process?
1755 to Up to 95 MHz NTIA study. Ten year process?
1850 MHz
• Roughly 500 MHz allocated for Commercial Mobile Radio Spectrum
• Rysavy Research and FCC models show looming spectrum crunch
• Congestion already occurring regularly
2 Copyright 2012 Rysavy Research

3. Urgent Need For Spectrum
Long process from first steps to use.
Shorter term:
• Mobile Satellite Services (MSS) spectrum
• 1755 -1780 MHz paired with 2155-2180
3 Copyright 2012 Rysavy Research

4. Spectrum Characteristics
• Harmonized bands
– Unusual bands inhibit ecosystems
– But all spectrum is valuable, e.g., WCS
• Band size
– LTE operates best in 10+10 MHz or higher
• Frequency
– Lower propagates further and penetrates better
• Spectral efficiency
– Depends on technology, not frequency
• Aggregation
– Possible with HSPA+, LTE
– Next best option after wider channels
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5. Downlink Spectral Efficiency
Spectral efficiency: bandwidth available from spectrum
Approaching theoretical limits – limited future gains
Further details:
http://www.rysavy.com/Articles/2011_09_08_Mobile_Broadband_Explosion.pdf, page 56
5 Copyright 2012 Rysavy Research

6. High versus Low Spectrum
Lower frequencies:
• Longer propagation
• Fewer cells required for coverage
• Better in-building penetration
Higher frequencies:
• Shorter propagation
• More cells required for coverage
• BUT higher capacity network
Spectral efficiency (bandwidth in spectrum) is equivalent!
Further details: http://www.hightechforum.org/low-versus-high-radio-spectrum/
6 Copyright 2012 Rysavy Research

7. Types of Deployment
Rural:
• Low capacity network
• Fewer cells desirable
Urban:
• High capacity network
• More cells needed
• Low/high frequencies
offer largely equivalent
performance
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8. Combining Low and High Bands
Low Frequencies:
• Larger cells
• Underlay for coverage
• Lower capacity
High Frequencies:
• Smaller cells
• Overlay for capacity
• Selectively deployed
E.g., airport
8 Copyright 2012 Rysavy Research

9. The Future: Heterogeneous Networks
4G Pico
Femto
4G Macro Cell
Femto
Femto 3G Macro Cell
Wi-Fi
3G Macro Cell
Manage:
Femto Wi-Fi
Mobility
Femto
Interference
Congestion
Femto Wi-Fi
QoS
Handoff Wi-Fi
Load balancing
Data offload Wi-Fi
Control traffic 4G Pico
Abuse Self-organizing
Attacks
Roaming
Self-optimizing
• HetNets (with small cells) can significantly increase capacity
• Methods defined in LTE-Advanced
• Backhaul remains fundamental challenge
• Long-term proposition
9 Copyright 2012 Rysavy Research

10. 700 MHz Interoperability
• Source: WT Docket No. 12-69,
http://transition.fcc.gov/Daily_Releases/Daily_Business/2012/db0321/FCC-12-31A1.pdf
• AT&T is in band class 17 (B/C blocks).
• Verizon is in band class 13 (Upper C block).
• Lower D block: unpaired, Qualcomm MediaFLO, now AT&T
• Small operators in band class 12 (A block).
• E block can operate at high power, so is additional source of interference for A band.
• Upper C band reversed with lower block used for transmit – right next to low band C
block transmit.
10 Copyright 2012 Rysavy Research

11. E-UTRA Uplink (UL) operating band Downlink (DL) operating band Duplex
Operating BS receive BS transmit Mode
Band UE transmit UE receive
FUL_low – FUL_high FDL_low – FDL_high
1 1920 MHz – 1980 MHz 2110 MHz – 2170 MHz FDD
LTE Bands Specified Globally
2 1850 MHz – 1910 MHz 1930 MHz – 1990 MHz FDD
3 1710 MHz – 1785 MHz 1805 MHz – 1880 MHz FDD
4 1710 MHz – 1755 MHz 2110 MHz – 2155 MHz FDD
3GPP Technical Specification 36.104, V11.0.0.
5 824 MHz – 849 MHz 869 MHz – 894MHz FDD
1
6 830 MHz – 840 MHz 875 MHz – 885 MHz FDD
7 2500 MHz – 2570 MHz 2620 MHz – 2690 MHz FDD
8 880 MHz – 915 MHz 925 MHz – 960 MHz FDD
9 1749.9 MHz – 1784.9 MHz 1844.9 MHz – 1879.9 MHz FDD
10 1710 MHz – 1770 MHz 2110 MHz – 2170 MHz FDD
11 1427.9 MHz – 1447.9 MHz 1475.9 MHz – 1495.9 MHz FDD
12 699 MHz – 716 MHz 729 MHz – 746 MHz FDD
13 777 MHz – 787 MHz 746 MHz – 756 MHz FDD
14 788 MHz – 798 MHz 758 MHz – 768 MHz FDD
15 Reserved Reserved FDD
16 Reserved Reserved FDD
17 704 MHz – 716 MHz 734 MHz – 746 MHz FDD
18 815 MHz – 830 MHz 860 MHz – 875 MHz FDD
19 830 MHz – 845 MHz 875 MHz – 890 MHz FDD
20 832 MHz – 862 MHz 791 MHz – 821 MHz
21 1447.9 MHz – 1462.9 MHz 1495.9 MHz – 1510.9 MHz FDD
22 3410 MHz – 3490 MHz 3510 MHz – 3590 MHz FDD
23 2000 MHz – 2020 MHz 2180 MHz – 2200 MHz FDD
24 1626.5 MHz – 1660.5 MHz 1525 MHz – 1559 MHz FDD
25 1850 MHz – 1915 MHz 1930 MHz – 1995 MHz FDD
26 814 MHz – 849 MHz 859 MHz – 894 MHz FDD
...
33 1900 MHz – 1920 MHz 1900 MHz – 1920 MHz TDD
34 2010 MHz – 2025 MHz 2010 MHz – 2025 MHz TDD
35 1850 MHz – 1910 MHz 1850 MHz – 1910 MHz TDD
36 1930 MHz – 1990 MHz 1930 MHz – 1990 MHz TDD
37 1910 MHz – 1930 MHz 1910 MHz – 1930 MHz TDD
38 2570 MHz – 2620 MHz 2570 MHz – 2620 MHz TDD
39 1880 MHz – 1920 MHz 1880 MHz – 1920 MHz TDD
40 2300 MHz – 2400 MHz 2300 MHz – 2400 MHz TDD
41 2496 MHz – 2690 MHz 2496 MHz – 2690 MHz TDD
42 3400 MHz – 3600 MHz 3400 MHz – 3600 MHz TDD
43 3600 MHz – 3800 MHz 3600 MHz – 3800 MHz TDD
11 Note 1: Band 6 is not applicable.
Copyright 2012 Rysavy Research

12. Carrier Aggregation Release 10 Timeframe
• Intra-band contiguous:
– Band 1 (FDD), UL[1920-1980]/DL[2110-2170]
– Band 40 (TDD), UL[2300-2400]/DL[2300-2400]
• Inter-band non-contiguous (FDD):
– Band 1 (UL[1920-1980]/DL[2110-2170]) + Band 5 (UL[824-
849]/DL[869-894])
Release 10 LTE-Advanced UE resource pool
Rel’8 Rel’8 Rel’8 Rel’8 Rel’8
100 MHz bandwidth
20 MHz Release 8 UE uses a
single 20 MHz block
12 Copyright 2012 Rysavy Research

13. Carrier Aggregation Release 11 Timeframe
• Expanded CA combinations, all inter-band, non-
contiguous, and FDD, include:
– Band 3 and Band 7 (TeliaSonera – 1800MHz+2600 MHz)
– Band 4 and Band 13 (Verizon – AWS + Upper 700 MHz)
– Band 4 and Band 17 (AT&T – AWS + Lower 700 MHz)
– Band 2 and Band 17 (AT&T – PCS + Lower 700 MHz)
– Band 4 and Band 5 (AT&T – AWS + 850 MHz)
– Band 4 and Band 12 (Cox Communications – AWS + Lower 700
MHz)
– Band 5 and Band 12 (US cellular – 850 MHz + Lower 700 MHz)
– Band 5 and Band 17 (AT&T – 850 MHz + Lower 700 MHz)
– Band 7 and Band 20 (Orange – 2600 MHz + 800 MHz)
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14. dawn of the mobile broadband era
• Spectrum crunch is real
• Networks can be built with
either low or high bands
• Low and high bands can be
combined for high coverage
and high capacity
• Carrier aggregation will play
an important role
• Future technologies such as
small cells help – but are very
complicated
14 Copyright 2012 Rysavy Research