Simulation Results for Opportunistic Relay, Customer Premise Relay, and Direct Link Usage Models
IEEE 802.16 Presentation Submission
Document Number:
IEEE C802.16m-08/494
Date Submitted:
2008-05-09
Source:
Jeff Bonta, George Calcev, Steve Emeott
Voice:
Motorola
E-mail:
jeff.bonta@motorola.com
Venue:
[802.16m] [16jm] Session #55, 12-15 May, 2008
IEEE802.16m-08/016r1: Call for Contributions on Project 802.16m System Description Document (SDD)
Base Contribution:
N/A
Purpose:
For discussion in TGm, this contribution presents simulation results to demonstrate the benefits of Opportunistic Relay, Customer Premise
Relay, and Direct Link Usage Models
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Simulation Results for Opportunistic Relay, Customer
Premise Relay, and Direct Link Usage Models
• Motivation
– Contribution C80216m-08/270r1 has introduced usage model examples
for 16m Ad hoc Relay
– 16jm Ad Hoc Group recommendations on basic constructs for 16m
relay usage models
• The basic constructs include:
– MS-MS direct communication,
– MS relaying for an out-of-coverage MS, and
– MS relaying for an in-coverage MS
• These MS relaying and direct link constructs are being recommended to be
classified as out of scope in the SDD
• Proposal
– With consideration of performance results in this presentation, it is
proposed that these constructs be considered in scope of 16m relay
2
Topologies for Simulated Usage Models
•
•
Opportunistic Relay and Customer Premise
Relay usage models were simulated
Simulated system topology consisted of:
–
–
–
19 cells with results tabulated from center cluster
of 7cells
Manhattan style street grid with 100 meters city
blocks with buildings
Assumed relay antenna at a building edge is
outside of the building
•
–
•
No interior relays were allowed
Both active and standby MS are permitted to
relay
•
–
Example Monte Carlo drop of active and idle MS in urban
environment of a 16m system deployment with 750m cell radius
Assumed that the total user density is made up of
idle and active users. A typical system will have 3%
of the users active in a call. We used ~5%.
2x2 MIMO assumed for BS and MS
Examples show:
–
–
Distance between peer nodes is within 90m and
Not all relayed nodes are at fringe of cell
Key:
Active MS
Streets / Buildings
BS
.
Idle MS
o
Ad Hoc
Link
MS
PMP Link
Relay
Link
RS
BS-RS
RS-MS
3
Simulation Results for Opportunistic
and CP Relay Usage Models
• Simulation Conditions
– User density (active + idle) was set at 168 users/km2
• 4.8% of users are assumed to be active in a call (i.e. 8 users/km2)
• Explanation of Results
– Good-put is the effective bits transferred per frame, adjusted for the overhead of
a single sub-frame ad hoc zone (AHZ)
• Good-put gains represent overhead adjusted throughput per frame (relayed and PMP
connections) vs. a PMP solution with no AHZ
– Approximately 50% of connections are relayed, but only 2.5% of the idle user
base performs a relay
Configuration
46 dBm BS Tx
Power, 750m cell
radius
33 dBm BS Tx
Power, 1000m
cell radius
Average
“Good-put” Gain
(all connections)
Relay Only
“Good-put”
Gain
71.8%
176.4%
104.8%
337.7%
4
Direct Link Simulated Usage Model
•
•
Peer-to-Peer usage models were simulated in direct
link configurations
Direct Link MS pairs were uniformly distributed
throughout cell area
–
–
•
•
•
No direct links were used where both MS are inbuilding
Only those in-coverage MS pairs that were capable
of a 64 QAM transmission were considered
Direct Link “good-put” between each MS pair is
compared with the alternative UL/DL PMP “goodput”
•
–
PMP Links
Rate dependant on
channel conditions
Environment consisted of a Manhattan style street
grid with 100 meters city blocks with buildings
•
–
BS
MS
Direct Link
MS
64 QAM
Good-put on 1-hop P2P links and 2-hop PMP links
assumes a 1 frame transfer
Lowest data rate of the two PMP links is used for goodput calculation since it is the limiting link.
Good-put is computed by reducing the throughput of
the P2P link to compensate for the AHZ overhead.
Results tabulated from center cluster of 7cells
6.3x Average Good-put Gain Observed for Direct
Link over PMP connection
5
Simulation Assumptions and Parameters
• 16m Evaluation Methodology parameters were used.
Options and exceptions are:
– Manhattan style urban environment included
– 16m Outdoor to Indoor pathloss model used for BS to inbuilding MS
– MS-MS pathloss model derived from field tests. Pathloss
exponents:
• 2.4 LOS (assume no tree canopy on streets), 3.1 around street corner
up to 100 meters, 4.2 around street corner beyond 100 meters, and 4.2
into building.
• Simulated system operation:
– Out-of-coverage MS are excluded from results
• Out-of-coverage uplink occurs when MS cannot reach BS at QPSK
rate ½ with 4 repetitions
• Out-of-coverage downlink occurs when BS cannot reach MS at QPSK
rate ½ with 2 repetitions
6