1. Per-User Data Rate, Band and Bandwidth Options for VHT
July 2007
doc.: IEEE /2090r0
September 2007
Per-User Data Rate, Band and Bandwidth Options for VHT
Date:
Authors:
Slide 1
Jason A. Trachewsky, et. al. (Broadcom Corporation)
Eldad Perahia (Intel)

2. What Per-User Data Rates Do We Want to Support?
3-5+ Gbps
New applications like wireless docking, thin clients, etc.
Supporting small numbers of users, probably non-simultaneous
Mbps
Traditional WLAN applications
Supporting large numbers of possibly-simultaneous users
Must we choose?
Jason A. Trachewsky, et. al. (Broadcom Corporation)

3. Band and Bandwidth Options
fc < 6 GHz
fc > 57 GHz
BW < 100 MHz
BW > 100 MHz
BW < 500 MHz
BW > 500 MHz
Data rate limit around 1 Gbps
Data rates > 1 Gbps, fc > 5 GHz
Data rate limit around 1 Gbps
Data rates up to several Gbps
Jason A. Trachewsky, et. al. (Broadcom Corporation)

4. Band Challenges < 6 GHz > 57 GHz
Existing a and n users
20/40/x (x = 80, 120, 160, ??) coex!!
Only about 100 MHz of spectrum available in some regulatory domains
> 57 GHz
No existing standardized communication systems
TG3c is hard at work, defining WPAN in the GHz band
Plan to use ~2 GHz at one time
Far greater path and materials absorption losses
Jason A. Trachewsky, et. al. (Broadcom Corporation)

5. The 5-6 GHz Regulatory Situation
U-NII Low/Middle Bands and ETSI Low Band
U-NII High Band
MHz
MHz
MHz
MHz
lower* middle* upper band
40mW mW mW Pmax
indoor indoor outdoor
* +23 dBm EIRP for ETSI
ETSI High Band
MHz
upper band
+30 dBm* EIRPmax
* except for ch. 140
+23 dBm EIRP
MHz
Additional channels from 4920 to 5080 MHz are defined only in Japan.
Jason A. Trachewsky, et. al. (Broadcom Corporation)

6. The 60 GHz Opportunity
Up to 9 GHz of unlicensed/licensed-free spectrum available in some regulatory domains (57-66 GHz).
This huge amount of spectrum available at reasonably-high to very high power spectral density and EIRP.
 the possibility of actually achieving > 1 Gbps on the air at > 1 m range!
Jason A. Trachewsky, et. al. (Broadcom Corporation)

7. The Worldwide 60 GHz Regulatory Situation
Geographically Available 60 GHz Spectrum & Power 57 58 59 60 61 62 63 64 6 5
GHz
59.4
62.9
Australia
Canad a
Japan
USA
Other Considerations
Output Power
Region
Min. BW = 100 MHz
500 mW
peak 47
dBi
max Ant. Gain
+50, -
70%
Pow
. Change OT&TTR 10
into Antenna
Canada
150 W peak EIRP
Note:
China currently has no 60 GHz regulations and there is no effort under way in China to put 60 GHz regulations in place.
Jason A. Trachewsky, et. al. (Broadcom Corporation)

8. 60 GHz Regulatory Issues Focus: EU
Frequency band
Maximum transmit power
Duty cycle
Channel spacing
Notes
A minimum spectrum requirement of 500 MHz is requested.
+57 dBm e.i.r.p. (+20 dBm nominal with up to +37dBi antenna gain or +10 dBm nominal with up to +47dBi antenna gain)
No restriction
The transmit power is necessary to offset oxygen and material attenuation at this band, and is typical for gigabit commercial product in this band
NOTE: A license-exempt scheme is proposed to the National Regulatory Authorities for applications other than aeronautical mobile and inter-satellite communications. Users may not claim protection from interference from other users within the same spectrum for this kind of application.
Jason A. Trachewsky, et. al. (Broadcom Corporation)

9. 60 GHz Propagation and Link Budget Summary
Relative to 5 GHz band
60 GHz has 6-10 times the available bandwidth
21 dB additional path loss (excluding shadowing effects)
dB less transmitter power*
greater antenna gain (and more elements) possible in small volumes
significantly greater loss through building materials
Near-term significantly greater cost
LOS channels at limited range can achieve data rates > 2 Gbps with simple transceivers
NLOS channels can also achieve > 2 Gbps rates, but will require higher-complexity transceivers
* This is not a fundamental limit and certainly may be debated.
Jason A. Trachewsky, et. al. (Broadcom Corporation)

10. Simple 60 GHz Link Budget Example1 2 3 4 5 6 7 8 9 10 11
Range (m)
Practical Capacity (bps)
60 GHz Practical Capacity - 2 GHz Channel, IBM Model
-3 sd shadowing
mean
+3 sd shadowing
Ptx = +10 dBm
Gtx = +10 dBi
Grx = +10 dBi
Ntx = Nrx = 1
NF = 8 dB
Gap from capacity = 7 dB
Even with severe shadowing, Gbps at 2 m is feasible with one antenna.
Channel parameters from private home model, /191
Jason A. Trachewsky, et. al. (Broadcom Corporation)

11. Going Forward
VHT SG needs to limit the scope of possible bands, bandwidths and per-user data rates to consider.
Practical band choices include 5-6 GHz and GHz.