L1A L23 Interface » History » Version 1
laforge, 02/19/2016 10:48 PM
describe the minimal required interface between L1A and L23
| 1 | 1 | laforge | = Minimalistic L1 interface = |
|---|---|---|---|
| 2 | 1 | laforge | |
| 3 | 1 | laforge | This is the description of the minimal interface between L1 and higher layers (L23) |
| 4 | 1 | laforge | neccessary to establish a dedicated channel with the cell and perform procedures like |
| 5 | 1 | laforge | LOCATION UPDATE or AUTHENTICAITON. |
| 6 | 1 | laforge | |
| 7 | 1 | laforge | == Message Types == |
| 8 | 1 | laforge | |
| 9 | 1 | laforge | === SYNC_NEW_CCCH_REQ === |
| 10 | 1 | laforge | |
| 11 | 1 | laforge | Triggers the following actions in L1: |
| 12 | 1 | laforge | * switch to new ARFCN |
| 13 | 1 | laforge | * perform AGC + AFC |
| 14 | 1 | laforge | * synchronize to FCCH |
| 15 | 1 | laforge | * decode SCH and determine frame number |
| 16 | 1 | laforge | |
| 17 | 1 | laforge | ==== parameters ==== |
| 18 | 1 | laforge | * ARFCN + BAND |
| 19 | 1 | laforge | |
| 20 | 1 | laforge | ==== response ==== |
| 21 | 1 | laforge | * SYNC_NEW_CCCH_RESP |
| 22 | 1 | laforge | |
| 23 | 1 | laforge | |
| 24 | 1 | laforge | === SYNC_NEW_CCCH_RESP === |
| 25 | 1 | laforge | Sent from the L1 to the L23 after it has synchronized to a new cell (FCCH and SCH acquisition) |
| 26 | 1 | laforge | |
| 27 | 1 | laforge | ==== parameters ==== |
| 28 | 1 | laforge | * struct l1_info_dl |
| 29 | 1 | laforge | * ARFCN + BAND |
| 30 | 1 | laforge | * GSM frame number (t1/t2/t3) |
| 31 | 1 | laforge | * Rx Level |
| 32 | 1 | laforge | * SNR |
| 33 | 1 | laforge | * BSIC |
| 34 | 1 | laforge | |
| 35 | 1 | laforge | |
| 36 | 1 | laforge | === CCCH_INFO_IND === |
| 37 | 1 | laforge | |
| 38 | 1 | laforge | Sent by the L1 to the L23 whenever it has successfully decoded four consecutive bursts on |
| 39 | 1 | laforge | the CCCH. |
| 40 | 1 | laforge | |
| 41 | 1 | laforge | It is up to the L23 to decide whether the burst belongs to BCCH, AGCH, PCH or SDCCH/4. |
| 42 | 1 | laforge | |
| 43 | 1 | laforge | ==== parameters ==== |
| 44 | 1 | laforge | * ARFCN + BAND |
| 45 | 1 | laforge | * GSM frame number |
| 46 | 1 | laforge | * Rx Level |
| 47 | 1 | laforge | * SNR |
| 48 | 1 | laforge | * 33 bytes L1 payload |
| 49 | 1 | laforge | |
| 50 | 1 | laforge | |
| 51 | 1 | laforge | === RACH_REQ === |
| 52 | 1 | laforge | |
| 53 | 1 | laforge | Sent from the L23 to the L1 to instruct the L1 to send a RACH request to the current cell. |
| 54 | 1 | laforge | |
| 55 | 1 | laforge | ==== parameters ==== |
| 56 | 1 | laforge | * struct l1_info_ul |
| 57 | 1 | laforge | * Tx power |
| 58 | 1 | laforge | * TDMA frame number |
| 59 | 1 | laforge | * channel type |
| 60 | 1 | laforge | * channel number (timeslot, subslot) |
| 61 | 1 | laforge | * 8 bit RA Reference |
| 62 | 1 | laforge | |
| 63 | 1 | laforge | |
| 64 | 1 | laforge | ==== response ==== |
| 65 | 1 | laforge | No response by L1. |
| 66 | 1 | laforge | |
| 67 | 1 | laforge | The response by the serving cell will be an IMMEDIATE ASSIGNMENT in the AGCH on |
| 68 | 1 | laforge | the CCCH downlink. |
| 69 | 1 | laforge | |
| 70 | 1 | laforge | |
| 71 | 1 | laforge | === DEDIC_MODE_EST_REQ === |
| 72 | 1 | laforge | |
| 73 | 1 | laforge | Sent from the L23 to the L1 to instruct switching from CCCH mode to a dedicated |
| 74 | 1 | laforge | channel. |
| 75 | 1 | laforge | |
| 76 | 1 | laforge | Initially we only implement SDCCH/4 and SDCCH/8 on a non-hopping cell. |
| 77 | 1 | laforge | |
| 78 | 1 | laforge | ==== parameters ==== |
| 79 | 1 | laforge | * struct l1_info_ul |
| 80 | 1 | laforge | * (arfcn|hsn,maio) |
| 81 | 1 | laforge | |
| 82 | 1 | laforge | |
| 83 | 1 | laforge | === DEDIC_MODE_DATA_IND === |
| 84 | 1 | laforge | |
| 85 | 1 | laforge | Sent by the L1 to the L23 to convey the successful reception of four |
| 86 | 1 | laforge | consecutive bursts on the dedicated channel. |
| 87 | 1 | laforge | |
| 88 | 1 | laforge | It is up to the L23 to do the time demultiplex of multiple SDCCHs in the same |
| 89 | 1 | laforge | on-air timeslot. |
| 90 | 1 | laforge | |
| 91 | 1 | laforge | ==== parameters ==== |
| 92 | 1 | laforge | * struct l1_info_dl |
| 93 | 1 | laforge | * 33 bytes L1 payload |
| 94 | 1 | laforge | |
| 95 | 1 | laforge | |
| 96 | 1 | laforge | === DEDIC_MODE_DATA_REQ === |
| 97 | 1 | laforge | Sent by the L23 to the L1 to send payload data on a dedicated channel such as |
| 98 | 1 | laforge | SDCCH. |
| 99 | 1 | laforge | |
| 100 | 1 | laforge | ==== parameters ==== |
| 101 | 1 | laforge | * struct l1_info_ul |
| 102 | 1 | laforge | * 33 byte L1 payload |
