1. Why 20 MHz Channelization in HTSG?
John Terry, Ph.D
NRC Dallas
John Terry Nokia

2. 20 MHz Channels & the PAR and 5 Criteria
Broad Market Potential
In order to obtain the broadest market, the HT standard must be a global standard
Hence, channel bonding is not suitable for global standardization since it does not meet the European regulatory specification of 20 MHz channelization
Economic Feasibility
Technically, channel bonding is feasible; however, it does not increase aggregatenetwork capacity by itself
Thus, can MIMO technology and channel bonding both be developed cost effectively?
Most of the available cost data for RF chains are based on 20 MHz channelization designs
Distinct Identity
HTTG will result in a wireless LAN with higher throughput than provided by a, b and g.
Neither channel bonding nor UWB meets this criterion on a per Hz basis.
John Terry Nokia

3. Aggregate Network Capacity Study
John Terry Nokia

4. Path Loss Models Wideband PCS Model from Feuerstein
Line of Sight (LOS)
Obstructed Line of Sight (OBS)
4.16
3.36
3.29
OBS n
LOS n n2
Transmitter Antenna Height
2.69
2.07
High (13.3m)
2.56
2.17
Medium (8.5m)
2.58
2.18
Low (3.7m)
Fresnel distance
Reference path
loss (1 meter)
Feuerstein, M.J., Blackard, K.L., Rappaport, T.S., Seidel, S.Y., and Xia, H.H., “Path Loss, Delay Spread and Outage Models as Functions of
Antenna Height for Microcellular System Design,” IEEE Transactions on Vehicular Technology, Vol. 43, No 3, pp August 1994.
John Terry Nokia

5. Simulator Approach – Seven Frequencies
Center cell is the reference
Center cell is randomly populated
with 1 – 20 users
Each of the six adjacent cells with
the same frequency is also
populated with 1 – 20 users
Interference is calculated for
the six strongest interferers to
the center of the reference cell 1 7 2 3 4 6 5
John Terry Nokia

6. Simulator Approach – Four Frequencies
Center cell is the reference
Center cell is randomly populated
with 1 – 20 users
Each of the six adjacent cells with
the same frequency is also
populated with 1 – 20 users
Interference is calculated for
the eight strongest interferers to
the center of the reference cell
Note that four interferers
dominate 1 4 2 3
John Terry Nokia

7. Capacity Study Assumptions
Link closes at 1% PER
Channel bonding PER performance has 3 dB penalty compared to the corresponding a performance due to the doubling of the noise bandwidth for the same tx power.
Capacity for both channel bonding and non-bonding cases are computed using reuse factors (Fr) of 4 and 7.
Bonding case will require reuse factor of 4 while non-bonding case, 7.
The base rate set for channel bonding without any antenna enhancements includes a mandatory and option rates plus 108 Mbps data rate at a SNR for 54 Mbps
Non-bonding base rate set includes a mandatory rates plus 4 additional rates greater than 54 Mbps but less than 100 Mbps using diversity techniques
STAs are randomly distributed in the cell and uniformly powered
Rates are assigned based upon signal-to-interference plus noise ratio
“Simulation” is done 2000 times and the average Mbps for the center cell is calculated
John Terry Nokia

8. Simulation Parameters
Each cell has 10 users uniformly distributed throughout the cell
The cell radium is varied 20m, 30m, and 40m
The transmit antenna has 6 dBi gain
The receive antenna has 6 dBi gain
Transmit power is set to 17 dBm
The average fading statistic for the subcarriers is used to compute the instantaneous SNR for link analysis
Performance for non-line of sight transmission is computed
The number of occurrences of the capacity (bps/Hz) for each of the rate in the basic rate set is plot in a histogram
The cdf of the capacity is computed
The total aggregate throughput is tabulated
John Terry Nokia

9. Capacity Histograms Channel bonding with reuse factor 4
Non-bonding with reuse factor 7
John Terry Nokia

10. Capacity CDF’s Channel bonding with reuse factor 4
Non-bonding with reuse factor 7
John Terry Nokia

11. Average Data Rate per Cell
Cell Radius
R=20 m
25.5 Mbps
Cell Radius R=30 m
25.96 Mbps
Cell Radius R=40m
HT, FR=7
25.33 Mbps
HT,
Single Cell
96 Mbps
95.32 Mbps
92.4 Mbps
Bonding, FR=4
11.31 Mbps
11.23 Mbps
10.54 Mbps
Bonding, Single Cell
104.2 Mbps
89.57 Mbps
74.1 Mbps
John Terry Nokia

12. Conclusion
To meet several of the 5 criteria and the PAR, 20 MHz channelization is desirable.
Channel bonding doesn’t increase the capacity nor improvement performance over a or g
Adopt 20 MHz channelization for HTSG
John Terry Nokia