1 Introduction
1.1 Motivation
1.2 Methodology
2 Related work
2.1 LTE-A RN and TDD
DL/UL configuration | Subframe no. | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
0 | D | S | U | U | U | D | S | U | U | U |
1 | D | S | U | U | D | D | S | U | U | D |
2 | D | S | U | D | D | D | S | U | D | D |
3 | D | S | U | U | U | D | D | D | D | D |
4 | D | S | U | U | D | D | D | D | D | D |
5 | D | S | U | D | D | D | D | D | D | D |
6 | D | S | U | U | U | D | S | U | U | D |
Backhaul link configuration | Access link configuration | Subframe no. | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | ||
0 | 1 | D | U | ||||||||
1 | U | D | |||||||||
2 | D | U | D | ||||||||
3 | U | D | D | ||||||||
4 | U | D | U | D | |||||||
5 | 2 | U | D | ||||||||
6 | D | U | |||||||||
7 | U | D | D | ||||||||
8 | D | U | D | ||||||||
9 | U | D | D | D | |||||||
10 | D | U | D | D | |||||||
11 | 3 | U | D | D | |||||||
12 | U | D | D | D | |||||||
13 | 4 | U | D | ||||||||
14 | U | D | D | ||||||||
15 | U | D | D | ||||||||
16 | U | D | D | D | |||||||
17 | U | D | D | D | D | ||||||
18 | 6 | U | D |
2.2 Previous work of LBPS
3 Proposed integrated sleep scheduling
3.1 Basic idea
3.2 Calculation of virtual subframe capacity
Notation | Definition(unit) |
---|---|
VSCBk | Backhaul subframe capacity (bit per subframe) |
VSCAi | Subframe capacity for access link Ai of RNi (bit per subframe) |
λ
i
| DL arrival rate for RNi (bit per subframe) |
N
Ai
| Estimated number of virtual subframe for RNi to transmit accumulated DL data to UEs in a sleep cycle |
N
Bk-Ai
| Estimated number of virtual subframe for DeNB to transmit the accumulated DL data to RNi on the backhaul link in a sleep cycle |
DataAcci | Estimated amount of accumulated DL data for RNi in a given cycle time (bit) |
3.3 Top-down LBPS schemes
3.4 Bottom-up LBPS schemes
3.5 Mapping mechanism
4 Simulation results and discussion
System bandwidth | 20 MHz (#RB = 100) |
---|---|
(#RN, #UE) | (6, 240) |
Load distribution | Equal load, hot spot |
Backhaul link quality | CQI 10~15 |
Access link quality | CQI 7~9 |
TDD configuration | C17 (C4 for access links) |
Packet size | 800 bits |
LBPS schemes parameters | |
Data_TH | Threshold of data accumulation |
Prob_TH | 0.8 |
Contrast scheme Std-DRX parameters |
4.1 Comparison of the mapping mechanisms
4.2 Results under equal load
4.3 Results under hot spot
4.4 Discussion on complexity and performance
Complexity (# of iterations in the worst case) | Performance (under equal load) | |||||
---|---|---|---|---|---|---|
First step | Second step per RN | Total | RN’s PSE | UE’s PSE | Delay | |
TD-Aggr | 1 | 1 | 1 + m | 1 | 1 | 1 |
TD-Merge | log2(m) | 1 | log2(m) + m | 2.0 | 1.34 | 1.95 |
TD-Split |
m
| 1 | m + m | 2.06 | 1.39 | 1.97 |
First step per RN | Second step | |||||
BU-Aggr | 1 | 1 | m + 1 | 1.92 | 1.34 | 1.81 |
BU-Merge | log2(n) | 1 | mlog2(n) + 1 | 2.16 | 1.59 | 2.41 |
BU-Split |
n
| 1 | mn + 1 | 2.33 | 1.61 | 5.12 |