Dimetra EBTS » History » Version 3
laforge, 02/19/2016 10:52 PM
add outline
1 | 3 | laforge | [[PageOutline]] |
---|---|---|---|
2 | = Motorola Dimetra EBTS = |
||
3 | |||
4 | 1 | laforge | The Motorola Dimetra EBTS is a TETRA Base Station design. |
5 | |||
6 | We have been able to get our hands on some of them. This page documents our knowledge about the units, their configuration and how to use them. |
||
7 | |||
8 | == Hardware == |
||
9 | |||
10 | === Motorola Dimetra Base Radio (T5931A) === |
||
11 | |||
12 | The Base Radio (BR) is a modular design in a 4U case, consisting of the following modules: |
||
13 | |||
14 | ==== Power Supply (CPN1031B) ==== |
||
15 | |||
16 | As the name suggests, it is merely a power supply, converting from the 48 V input to the various voltages required within the radio |
||
17 | |||
18 | ==== Controller (CAE010CMX) ==== |
||
19 | |||
20 | This is s small PowerPC based embedded system. It communicates with the TETRA Site Controller (TSC) over 10-Base-2 Ethernet |
||
21 | and controls all the other units of the Base Radio via the backplane of the BR cabinet. |
||
22 | |||
23 | It has the following connections: |
||
24 | * RS-232 on the back of the BR |
||
25 | * RS-232 on the front of the BR |
||
26 | * Site Alarm I/O on the back of the BR |
||
27 | * 10-Base-2 Ethernet on the back of the BR (BNC) |
||
28 | * Clock input on the back of the BR (BNC) |
||
29 | |||
30 | 2 | laforge | For more details see [[wiki:Dimetra_EBTS/Base_Radio/Controller]] |
31 | |||
32 | 1 | laforge | ==== 3x Diversity Receiver (CTX1090A) ==== |
33 | |||
34 | This is the receiver. It has three antenna inputs in order to use antenna diversity for additional signal gain. |
||
35 | |||
36 | The received and demodulated TETRA bursts are forwarded to the Controller via the BR backplane. |
||
37 | |||
38 | 2 | laforge | For more details see [[wiki:Dimetra_EBTS/Base_Radio/Receiver]] |
39 | |||
40 | 1 | laforge | ==== Exciter (CLN1510A) ==== |
41 | |||
42 | This is the transmitter. It receives TETRA frames from the Controler via the backplane and encodes/modulates them. The output |
||
43 | is fed into the power amplifier over a SMA jumper connection on the back of the base radio. |
||
44 | |||
45 | 2 | laforge | For more details see [[wiki:Dimetra_EBTS/Base_Radio/Exciter]] |
46 | |||
47 | 1 | laforge | ==== Power Amplifier (CTX1030A) ==== |
48 | |||
49 | This is a RF power amplifier, used to generate a high-power signal from the output of the exciter. |
||
50 | |||
51 | It has three coaxial connections on the back, which are used as follows: |
||
52 | * input from the exciter |
||
53 | * feedback from PA into the exciter |
||
54 | * actual RF power output (towards antenna) |
||
55 | |||
56 | 2 | laforge | For more details see [[wiki:Dimetra_EBTS/Base_Radio/Amplifier]] |
57 | |||
58 | 1 | laforge | === Integrated Site Controller (CLN1480A) === |
59 | |||
60 | This is a unit that interfaces up to 8 Base Radios with the core network of the Dimetra TETRA network (SwMI). |
||
61 | |||
62 | Hardware-wise, it is a PowerPC based system, looking very much like an old-fashioned PC mainboard with |
||
63 | both ISA and PCI slots. |
||
64 | |||
65 | The mainboard houses the PowerPC CPU and it has slots for RAM. |
||
66 | |||
67 | There are some extension cards plugged into the system: |
||
68 | * Clock generation card (ISA, full length). |
||
69 | * has an integrated GPS receiver, to which you attach a GPS antenna |
||
70 | * generates the reference 5MHz clock distributed over Coaxial cable to the Base Radios |
||
71 | * Ethernet Card using DEC tulip chipset (PCI) |
||
72 | * This card is what talks to the Base Radios (BR) via 10-Base-2 |
||
73 | * Unknown card with RJ-45 jack (REDUND) on the back. Might be E1 |
||
74 | |||
75 | There are further inputs and outputs on the system: |
||
76 | * A DB-15 jack for X.21 synchronous serial backhaul (2048Mbps) |
||
77 | * FIXME |
||
78 | * A RS-232 serial port for local configuration |
||
79 | 2 | laforge | |
80 | For more details see [[wiki:Dimetra_EBTS/Site_Controller]] |
||
81 | 1 | laforge | |
82 | === RF Distribution System (CFX4041A) === |
||
83 | |||
84 | This is a sophisticated combiner for the high-power output signals of the PA of up to 4 Base Radios. |
||
85 | |||
86 | In order to ensure optimal impedance matching, the combiner is mechanically tuned by electrical motors |
||
87 | which are controlled by some control logic. |
||
88 | |||
89 | The combiner inside the system has the following connections (external connections in '''bold'''): |
||
90 | * '''4 high-power radio input ports''' (N socket on the front, one close to each motor) |
||
91 | * this is where the RF signal emitted by the PA of the BR enters |
||
92 | * 4 RF taps, one for each of the high-power radio inputs |
||
93 | * they are connected to the controller unit attached to the inside of the front lid |
||
94 | * 1 high-power radio output port (N socket) |
||
95 | * this output is connected to a power meter inside the same cabinet |
||
96 | * 4 stepper motor electrical connections |
||
97 | * connected to the controller unit attached to the inside of the front lid |
||
98 | * RS-232 serial line for control+monitoring |
||
99 | * this is a DB-9 port of the controller unit attached to the inside of the front lid |
||
100 | * interconnected to one of the Base Radios (typically BR1) inside the rack |
||
101 | |||
102 | The flow of the signals is as follows: |
||
103 | * RF from the PA enters at the four combiner inputs |
||
104 | * combined RF output leaves through central output of the combiner, from where |
||
105 | * it is routed to the FR power meter |
||
106 | * whose output socket is routed to the transmit antenna (or a duplexer in case of a shared Rx/Tx antenna) |
||
107 | |||
108 | {{{ |
||
109 | #!graphviz |
||
110 | digraph G { |
||
111 | graph [ rankdir = LR ]; |
||
112 | |||
113 | //{ rank=same; combiner; controller; }; |
||
114 | |||
115 | br1_pa_out -> combiner |
||
116 | br2_pa_out -> combiner |
||
117 | br3_pa_out -> combiner |
||
118 | br4_pa_out -> combiner |
||
119 | |||
120 | combiner -> power_meter |
||
121 | power_meter -> tx_antenna |
||
122 | |||
123 | combiner -> controller [ dir=both color=red ] |
||
124 | power_meter -> controller [ color=red ] |
||
125 | |||
126 | power_meter [ shape=box ]; |
||
127 | combiner [ shape=box ]; |
||
128 | controller [ shape=box ]; |
||
129 | |||
130 | |||
131 | |||
132 | } |
||
133 | }}} |
||
134 | === Rx LNA Multicoupler (CRX102A) === |
||
135 | |||
136 | The purpose of the Rx LNA multicoupler is to amplify the received signal from the antennas, and split |
||
137 | the signal so each Base Radio is attached to each antenna: |
||
138 | |||
139 | {{{ |
||
140 | #!graphviz |
||
141 | digraph G { |
||
142 | graph [ rankdir = LR ]; |
||
143 | |||
144 | antenna1 -> lna1 |
||
145 | antenna2 -> lna2 |
||
146 | antenna3 -> lna3 |
||
147 | |||
148 | lna1 -> multicoupler1 |
||
149 | lna2 -> multicoupler2 |
||
150 | lna3 -> multicoupler3 |
||
151 | |||
152 | multicoupler1 -> br1_rx1 |
||
153 | multicoupler1 -> br2_rx1 |
||
154 | multicoupler1 -> br3_rx1 |
||
155 | multicoupler1 -> br4_rx1 |
||
156 | |||
157 | multicoupler2 -> br1_rx2 |
||
158 | multicoupler2 -> br2_rx2 |
||
159 | multicoupler2 -> br3_rx2 |
||
160 | multicoupler2 -> br4_rx2 |
||
161 | |||
162 | multicoupler3 -> br1_rx3 |
||
163 | multicoupler3 -> br2_rx3 |
||
164 | multicoupler3 -> br3_rx3 |
||
165 | multicoupler3 -> br4_rx3 |
||
166 | |||
167 | lna1 [ shape=box label="LNA 1" ]; |
||
168 | lna2 [ shape=box label="LNA 2" ]; |
||
169 | lna3 [ shape=box label="LNA 3" ]; |
||
170 | multicoupler1 [ shape=box ]; |
||
171 | multicoupler2 [ shape=box ]; |
||
172 | multicoupler3 [ shape=box ]; |
||
173 | } |
||
174 | }}} |