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 = |
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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 |