Research Article
Enhancing Radio Access Network Performance over LTE-A for Machine-to-Machine Communications under Massive Access
Table 1
Simulation parameters.
| | Symbol | Parameter | Value |
| | B | Cell bandwidth | 5 MHz | | — | PRACH configuration index | 6 | | Total number of preambles | 54 | | Maximum number of preamble transmissions | 10 | | — | Number of UL grants per RAR | 3 | | — | Number of CCEs allocated for PDCCH | 16 | | — | Number of CCEs per PDCCH | 4 | | RA-Response Window Size | 5 ms | | — | mac-Contention Resolution Timer | 48 ms | | BO | Backoff timer | 20 ms | | — | Probability of successful delivery for both MSG3 and MSG4 | 90% | | Maximum number of HARQ transmissions for MSG3 and MSG4 (nonadaptive HARQ) | 5 | | M | Number of MTC devices (×103) | 5, 10, 16, 20, 25, 30 | | Tu | Number of available subframes over the distribution period | 10,000 | | b | Periodicity of PRACH opportunities | 5 ms | | MSG1 transmission time | 1 ms | | Preamble detection at eNB and MSG2 transmission time | 3 ms | | Device processing time before sending MSG3 | 5 ms | | MSG3 transmission time | 1 ms | | Time of processing MSG3 and sending MSG4 | 5 ms |
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