1 Copyright 2012 Rysavy Research

Spectrum Engineering Realities

Peter Rysavy

http://www.rysavy.com

July 2012

2 Copyright 2012 Rysavy Research

U.S. Spectrum Crunch

Frequency Band

Amount of Spectrum

Comments

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 1850 MHz

Up to 95 MHz NTIA study. Ten year process?

• Roughly 500 MHz allocated for Commercial Mobile Radio Spectrum

• Rysavy Research and FCC models show looming spectrum crunch

• Congestion already occurring regularly

3 Copyright 2012 Rysavy Research

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

4 Copyright 2012 Rysavy Research

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

5 Copyright 2012 Rysavy Research

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

6 Copyright 2012 Rysavy Research

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/

7 Copyright 2012 Rysavy Research

Types of Deployment

Rural:

• Low capacity network

• Fewer cells desirable

Urban:

• High capacity network

• More cells needed

• Low/high frequencies

offer largely equivalent

performance

8 Copyright 2012 Rysavy Research

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

9 Copyright 2012 Rysavy Research

The Future: Heterogeneous Networks

• HetNets (with small cells) can significantly increase capacity

• Methods defined in LTE-Advanced

• Backhaul remains fundamental challenge

• Long-term proposition

4G Macro Cell

3G Macro Cell

3G Macro Cell

4G Pico

Wi-Fi

Wi-Fi

Wi-Fi

Wi-Fi

Wi-Fi

Femto

Femto

Femto

Femto

Femto

Femto

4G Pico

Manage:

Mobility

Interference

Congestion

QoS

Handoff

Load balancing

Data offload

Control traffic

Abuse

Attacks

Roaming

Self-organizing

Self-optimizing

10 Copyright 2012 Rysavy Research

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.

11 Copyright 2012 Rysavy Research

E-UTRA Operating

Band

Uplink (UL) operating band BS receive UE transmit

Downlink (DL) operating band BS transmit UE receive

Duplex Mode

FUL_low – FUL_high FDL_low – FDL_high

1 1920 MHz – 1980 MHz 2110 MHz – 2170 MHz FDD

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

5 824 MHz – 849 MHz 869 MHz – 894MHz FDD

61 830 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

Note 1: Band 6 is not applicable.

LT

E B

and

s S

pecifie

d G

loba

lly

3G

PP

Technic

al S

pecific

ation 3

6.1

04,

V11.0

.0.

12 Copyright 2012 Rysavy Research

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])

Rel’8

100 MHz bandwidth

Rel’8 Rel’8 Rel’8 Rel’8

Release 10 LTE-Advanced UE resource pool

Release 8 UE uses a single 20 MHz block

20 MHz

13 Copyright 2012 Rysavy Research

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)

14 Copyright 2012 Rysavy Research

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