The document discusses the challenges and strategies related to LTE backhaul, emphasizing the importance of construction, capacity planning, and spectrum utilization. It highlights the transition towards small cells, noting that this will introduce complexities and higher costs, necessitating innovations in microwave technology. Ultimately, it asserts that current backhaul solutions are insufficient until improvements make it more affordable and easier to deploy.

1. IEEE COMSOC PANEL
LTE BACKHAUL CHALLENGES,
SMALL CELLS AND THE
CRITICAL ROLE OF
MICROWAVE
PAUL KENNARD, CTO | AVIAT NETWORKS
1

3. LTE
(Lon
g Ter
m Ev
oluti
4G
on)
10x f
aster
QoS, than
3G
Low
All-I laten
P
cy
Low
Cost
3 AVIAT NETWORKS |

4. ?

5. LESSONS LEARNED #1
CONSTRUCTION
(not capacity) is key LTE challenge

6. LTE CAPACITY REQUIREMENTS
Theore&cal
Single
User
Data
Rate
Down/Up
[Mbps]
Close
Medium
Far
10MHz
43
/
14.4
28
/
9.5
14
/
4.8
real scenario is 100-150mbps backhaul per 3 sector cellsite
6 AVIAT NETWORKS | 20 AUGUST 2010

7. AND PROPER PLANNING EASES RING CAPACITY DEMANDS
50Mbps
50Mbps
Ring Capacity 300Mbps Gateway
Node
100Mbps
50Mbps
50Mbps
50Mbps
50Mbps
typical overbooking factor for mobile operator = ~3x
ring capacity ~100mbps in this case
7 AVIAT NETWORKS | 20 AUGUST 2010

8. Capacity
1 Gbit/s
400 Mbit/s
Cell-Site Capacity
100 Mbit/s
Time
Zone of Capacity Growth Maximum Cell-site Capacity
LTE cannot outstrip microwave capacity to cellsite

9. BECAUSE MICROWAVE HAS EVOLVED…
Strategy Technique
1. More Spectrum • Multiple channels with link aggregation
(More Hz) (incl CCDP) – leverage N+0
• ACM
2. More Spectral Efficiency • Higher modulations (512/1024 QAM, ACM)
(More Bits per Hz) • FEC redundancy
3. More “Effective” • Header optimization / suppression
Throughput • Payload compression
(More Data per Bit) • Asymmetrical RF
and is a high capacity transport solution

10. LESSONS LEARNED #2
MICROWAVE MEETS LTE
CAPACITY NEEDS
even for large rings and multi-cellsite links

11. FUTURE OF LTE BACKHAUL IS:
Small Cells!!!
11 AVIAT NETWORKS | FEBRUARY 2012

12. HOWEVER, SMALL CELLS WILL CHANGE THE BACKHAUL PARADIGM…
1. More sites
higher cost,
more complexity
2. Different sites
new technologies
and construction challenges will get far worse
12 AVIAT NETWORKS |

13. Wired
Wireless
Wireless
(fiber/cable/dsl)
(LOS)
(NLOS)
200+Mbps
(shared,
may
Capacity
10Gbps
1-­‐2Gbps
be
ok
for
HSPA)
Site
LocaLon
/
Not
available,
costly
LOS
Flexible.
NLOS
RestricLons
install
Parabolic
Depends
on
frequency.
Limited
for
pt-­‐mpt.
Backhaul
Distance
Long
distance
but
costly
Millimeter
wave
limited
Pt-­‐pt
ok
Latency
us
us
5-­‐10ms
(ok
for
HSPA)
CAPEX
Very
high
High
(today)
Low
OPEX
Low
Medium
Medium
Costly.
Unlicensed
Spectrum
N/A
Available
opLons
very
risky
meaning… none of today’s backhaul solutions will suffice

14. LESSONS LEARNED 3
SMALL CELL NOT SIGNIFICANT MARKET
until backhaul gets cheaper and easier

15. WHICH MEANS
FUNDAMENTAL INNOVATIONS WILL BE REQUIRED IN
FOUNDATIONAL MICROWAVE TECHNOLOGY…
all in one tiny box...
including antenna!
15 AVIAT NETWORKS | FEBRUARY 2012

16. OTHER NEW APPROACHES WILL NEED TO BE CONSIDERED
CACHING DISTRIBUTED INTELLIGENCE
16 AVIAT NETWORKS | 20 AUGUST 2010

17. and Microwave Networking solutions will emerge
Security
Redundancy
and
SynchronizaLon
ProtecLon
ACM,
RF
RouLng
opLmizaLons
Integrated,
IP
Others
(DPI,
QoS,
Bandwidth
management
Microwave
caching,
CDN,
Pla[orm
etc)
17 AVIAT NETWORKS | Microwave Dumb Pipe

18. TO ACHIEVE ALL THIS, WE NEED TO PAY
ATTENTION TO WHAT’S IMPORTANT…
AMC
Pacer
–
voted
worst
car
of
all
Lme!

19. THANK YOU
AVIAT NETWORKS |
20
19 AUGUST 2010