 |
Claims  |
|
|
We claim:
1. An apparatus for transmitting data from a first terminal to a second
terminal, comprising:
a plurality of bidirectional transmission links L.sub.i, for i equal to 1
through N, across which data may be transmitted, each transmission L.sub.i
having a first end and a second end, and the plurality including a first
transmission link L.sub.1 ;
test control means, connected at the first terminal to the first end of the
first transmission link L.sub.1, for communicating control signals in-band
across the first transmission link L.sub.1 ;
a plurality of repeaters R.sub.i, for i equal to 1 through N-1, each of the
repeaters connected to the second end of one transmission link L.sub.i in
the plurality and the first end of an other transmission link L.sub.i+1 in
the plurality, and including:
first means for repeating data transmitted from the one transmission link
L.sub.i for transmission on the other transmission link L.sub.i+1,
second means for repeating data transmitted from the other transmission
link L.sub.i+1 for transmission on the one transmission link L.sub.i ; and
means, responsive to the control signals on the one transmission link
L.sub.i, for looping back data transmitted from the one transmission link
L.sub.i for transmission on the one transmission link L.sub.i.
2. The apparatus of claim 1, wherein each repeater R.sub.i further
includes:
repeater control means, connected to the one transmission link L.sub.i, the
first means, the second means, and the means for looping back, and
responsive to prespecified control signals on the one transmission link
L.sub.i, for detecting the prespecified control signals and setting a
first state, a second state, a third state, and a fourth state, wherein,
the first state is entered in response to detection of a first prespecified
control signal during the fourth state,
the second state is entered in response to detection of a second
prespecified control signal during the first state,
the third state is entered in response to detection of the second
prespecified control signal during the second state, and
the fourth state is entered in response to detection of a third specified
control signal during the third state; and wherein
the first means and second means operate during the first state and the
fourth state, and the means for looping back operates during the third
state.
3. The apparatus of claim 2, wherein each repeater R.sub.i further
includes:
means, connected to the repeater control means, for generating and
supplying the first prespecified control signal for transmission on the
other transmission link L.sub.i+1 during the second state and the third
state; and
wherein in addition, the first state is entered in response to the
detection of the first prespecified control signal during the second
state.
4. The apparatus of claim 1, wherein the test control means includes:
an interface by which user commands are supplied; and
means, responsive to user commands, for generating a sequence of
prespecified control signals to enable then disable the means for looping
back in a determinate repeater R.sub.k.
5. The apparatus of claim 4, wherein the test control means further
includes:
means, responsive to user commands, for generating a sequence of test
signals for supply to the determinate repeater R.sub.k while the means for
looping back is enabled.
6. The apparatus of claim 4, wherein the test control means further
includes:
means, responsive to a condition of signals looped back from the
determinate repeater R.sub.k, for indicating a fault condition in the
determinate repeater R.sub.k.
7. The apparatus of claim 5, wherein the test control means further
includes:
means, responsive to a condition of test signals looped back from the
determinate repeater R.sub.k, for indicating a fault condition in the
determinate repeater R.sub.k.
8. The apparatus of claim 2, wherein the first prespecified control signal
is a first multibit code, the second prespecified control signal is a
second multibit code, and the third prespecified control signal is a third
multibit code.
9. The apparatus of claim 8, wherein the first multibit code is 010100100,
the second multibit code is 001101110, and the third multibit code is
110001110.
10. The apparatus of claim 1, wherein each repeater R.sub.i further
includes:
a housing encasing the first means, the second means, and the means for
looping back, the housing being no larger than 2.5 inches by 0.7 inches by
5.9 inches; and
a connector, coupled to the housing, for connecting the one transmission
link L.sub.i and the other transmission link L.sub.i+1 to the repeater
R.sub.i.
11. The apparatus of claim 3, wherein each repeater R.sub.i further
includes:
a housing encasing the first means, the second means, the means for looping
back, and the means for generating and supplying, the housing being no
larger than 2.5 inches by 0.7 inches by 5.9 inches; and
a connector, coupled to the housing, for connecting the one transmission
link L.sub.i and the other transmission link L.sub.i+1 to the repeater
R.sub.i.
12. The apparatus of claim 1, wherein:
each repeater R.sub.i includes means, responsive to prespecified control
signals on the one transmission link L.sub.i, for generating and supplying
a first prespecified control signal for transmission on the other
transmission link L.sub.i+1 ; and
the test control means includes,
an interface for receiving user commands, and
means, responsive to a user command, for generating the first, a second and
a third prespecified control signals to enable then disable the means for
looping back and to enable then disable the means for generating and
supplying in a determinate repeater R.sub.k, where k is an integer between
1 and N-1.
13. The apparatus of claim 12, wherein:
for determinate repeater R.sub.k, the first, second and third prespecified
control signals are generated in an initial sequence including the first
prespecified control signal, the second prespecified control signal, the
second prespecified control signal, and the third prespecified control
signal, followed by an iterative sequence repeated k-1 times if k is
greater than 1,
the iterative sequence including the second prespecified control signal,
the second prespecified control signal, and the third prespecified control
signal; and wherein
the means for looping back is enabled in response to the second
prespecified control signal and disabled in response to the third
prespecified control signal; and
the means for generating and supplying the first prespecified control
signal is enabled in response to the second prespecified control signal
and disabled in response to the first prespecified control signal or the
third prespecified control signal.
14. The apparatus of claim 1, wherein the test control means includes:
means for communicating with a remote test center according to a
prespecified protocol;
means, responsive to the prespecified protocol, for generating a sequence
of prespecified control signals to enable then disable the means for
looping back in a determinate repeater R.sub.k ; and
means, responsive to signals looped back from the determinate repeater
R.sub.k, for reporting to the test center, according to the prespecified
protocol, a fault condition on the determinate repeater R.sub.k.
15. The apparatus of claim 1, wherein:
each repeater R.sub.i includes means, response to prespecified control
signals on the one transmission link L.sub.i, for generating and supplying
a first prespecified control signal for transmission on the other
transmission link L.sub.i+1 ; and
the test control means includes,
means for communicating with a remote test center according to a
prespecified protocol,
means, responsive to the prespecified protocol, for generating the first ,
a second and a third prespecified control signals to enable then disable
the means for looping back and to enable then disable the means for
generating and supplying in a determinate repeater R.sub.k, and
means, responsive to a signal looped back from the determinate repeater
R.sub.k, for reporting to the test center, according to the prespecified
protocol, a fault condition on the determinate repeater R.sub.k.
16. The apparatus of claim 15, wherein:
for determinate repeater R.sub.k, the first, second and third prespecified
control signals are generated in an initial sequence including the first
prespecified control signal, the second prespecified control signal, the
second prespecified control signal, and the third prespecified control
signal, followed by an iterative sequence repeated k-1 times if k is
greater than 1,
the iterative sequence including the second prespecified control signal,
the second prespecified control signal, and the third prespecified control
signal; and wherein
the means for looping back is enabled in response to the second
prespecified control signal and disabled in response to the third
prespecified control signal; and
the means for generating and supplying the first prespecified control
signal is enabled in response to the second prespecified control signal is
disabled in response to the first prespecified control signal or the third
prespecified control signal.
17. The apparatus of claim 1, wherein:
the control signals include an address for a determinate repeater; and
the determinate repeater includes means, responsive to the address, for
enabling the means for looping back.
18. The apparatus of claim 1, further including:
second test control means, connected at the second terminal to the second
end of transmission link L.sub.N, for communicating control signals
in-band across the transmission link L.sub.N ; and
wherein each repeater further includes means, responsive to the control
signals on the other transmission link L.sub.i+1, for looping back data
transmitted from the other transmission link L.sub.i+ 1 for transmission
on the other transmission link L.sub.i+1.
19. An apparatus for transmitting data from a first terminal to a second
terminal, comprising:
a plurality of bidirectional T1 transmission links L.sub.i, for i equal to
1 through N, across which data may be transmitted, each transmission link
L.sub.i having a first end and a second end, and the plurality including a
first transmission link L.sub.1 ; and
test control means, connected at the first terminal to the first end of the
first transmission link L.sub.1, for communicating control signals in-band
across the first transmission link L.sub.1 ;
a plurality of repeaters R.sub.i, for i equal to 1 through N-1, each of the
repeaters connected to the second end of one transmission link L.sub.i in
the plurality of the first end of an other transmission link L.sub.i+1 in
the plurality, each repeater including,
first means for repeating data transmitted from the one transmission link
L.sub.i for transmission on the other transmission link L.sub.i+1,
second means for repeating data transmitted from the other transmission
link L.sub.i+1 for transmission on the one transmission link L.sub.i, and
means, responsive to the control signals on the one transmission link
L.sub.i, for looping back data transmitted from the one transmission link
L.sub.i for transmission on the one transmission link L.sub.i.
20. The apparatus of claim 19, wherein each repeater R.sub.i further
includes:
repeater control means, connected to the one transmission link L.sub.i, the
first means, the second means, and the means for looping back, and
responsive to prespecified control signals on the one transmission link
L.sub.i, for detecting the prespecified control signals and setting a
first state, a second state, a third state, and a fourth state, wherein
the first state is entered in response to detection of a first prespecified
control signal during the fourth state,
the second state is entered in response to detection of a second
prespecified control signal during the first state,
the third state is entered in response to detection of the second
prespecified control signal during the second state, and
the fourth state is entered in response to detection of a third
prespecified control signal during the third state; and wherein
the first means and second operate during the first state and the fourth
state, and the means for looping back operates during the third state.
21. The apparatus of claim 20, wherein each repeater R.sub.i, further
includes:
means, connected to the repeater control means, for generating and
supplying the first prespecified control signal for transmission on the
other transmission link L.sub.i+1 during the second state and the third
state; and
wherein in addition, the first state is entered in response to the
detection of the first prespecified control signal during the second
state.
22. The apparatus of claim 19, wherein the test control means includes:
an interface by which user commands are supplied; and
means, responsive to a user command, for generating a sequence of
prespecified control signals to enable then disable the means for looping
back in a determinate repeater R.sub.k.
23. The apparatus of claim 22, wherein the test control means further
includes:
means, responsive to the user command, for generating a sequence of test
signals for supply to the determinate repeater R.sub.k while the means for
looping back is enabled.
24. The apparatus of claim 22, wherein the test control means further
includes:
means, responsive to a condition of signals looped back from the
determinate repeater R.sub.k, for indicating a fault condition in the
determinate repeater R.sub.k.
25. The apparatus of claim 23, wherein the test control means further
includes:
means, responsive to a condition of test signals looped back from the
determinate repeater R.sub.k, for indicating a fault condition in the
determinate repeater R.sub.k.
26. The apparatus of claim 20, wherein the first prespecified control
signal is a first multibit code, the second prespecified control signal is
a second multibit code, and the third prespecified control signal is a
third multibit code.
27. The apparatus of claim 26, wherein the first multibit code is
010100100, the second multibit code is 001101110, the third multibit code
is 110001110.
28. The apparatus of claim 19, wherein each repeater R.sub.i further
includes:
a housing encasing the first means, the second means, and the means for
looping back, the housing being no larger than 2.5 inches by 0.7 inches by
5.9 inches; and
a connector, coupled to the housing, for connecting the one transmission
link L.sub.i and the other transmission link L.sub.i+1 to the repeater
R.sub.i.
29. The apparatus of claim 21, wherein each repeater R.sub.i further
includes:
a housing encasing the first means, the second means, the means for looping
back, and the means for generating and supplying, the housing being no
larger than 2.5 inches by 0.7 inches by 5.9 inches; and
a connector, coupled to the housing, for connecting the one transmission
link L.sub.i and the other transmission link L.sub.i+1 to the repeater
R.sub.i.
30. The apparatus of claim 19, wherein:
each repeater R.sub.i includes means, responsive to prespecified control
signals of the one transmission link L.sub.i, for generating and supplying
a first prespecified control signal for transmission on the other
transmission link L.sub.i+1 ; and
the test control means includes,
an interface for receiving user commands, and
means, responsive to a user command, for generating the first, a second and
a third prespecified control signals to enable then disable the means for
looping back and to enable then disable the means for generating and
supplying in a determinate repeater R.sub.k, where k is an integer between
1 and N-1.
31. The apparatus of claim 30, wherein:
for a determinate repeater R.sub.k, the first, second and third
prespecified control signals are generated in an initial sequence
including the first prespecified control signal, the second prespecified
control signal, the second prespecified control signal, and the third
prespecified control signal, followed by an iterative sequence repeated
k-1 times if k is greater than 1,
the iterative sequence including the second prespecified control signal,
the second prespecified control signal, and the third prespecified control
signal; and wherein
the means for looping back is enabled in response to the second
prespecified control signal and disabled in response to the third
prespecified control signal; and
the means for generating and supplying the first prespecified control
signal is enabled in response to the second prespecified control signal
and disabled in response to the first prespecified control signal or the
third prespecified control signal.
32. The apparatus of claim 19, wherein the test control means includes:
means for communicating with a remote test center according to a
prespecified protocol;
means, responsive to the prespecified protocol, for generating a sequence
of prespecified control signals to enable then disable the means for
looping back in a determinate repeater R.sub.k ; and
means, responsive to signals looped back from the determinate repeater
R.sub.k, for reporting according to the prespecified protocol a fault
condition on the determinate repeater R.sub.k to the test center.
33. The apparatus of claim 19, wherein:
each repeater R.sub.i includes means, responsive to prespecified control
signals on the one transmission link L.sub.i, for generating and supplying
a first prespecified control signal for transmission on the other
transmission link L.sub.i+1 ; and
the test control means includes,
means for communicating with a remote test center according to a
prespecified protocol,
means, responsive to the prespecified protocol, for generating the first, a
second and a third prespecified control signals to enable then disable the
means for looping back and to enable then disable the means for generating
and supplying in a determinate repeater R.sub.k, and
means, responsive to signal looped back from the determinate repeater
R.sub.k, for reporting to the test center, according to the prespecified
protocol, a fault condition on the determinate repeater R.sub.k.
34. The apparatus of claim 33, wherein:
for the determinate repeater R.sub.k, the first, second and third
prespecified control signals are generated in an initial sequence
including the first prespecified control signal, the second prespecified
control signal, the second prespecified control signal, and the third
prespecified control signal, followed by an iterative sequence repeated
k-1 times if k is greater than 1,
the iterative sequence including the second prespecified control signal,
the second prespecified control signal, and the third prespecified control
signal; and wherein
the means for looping back is enabled in response to the second
prespecified control signal and disabled in response to the third
prespecified control signal; and
the means for generating and supplying the first prespecified control
signal is enabled in response to the second prespecified control signal
and disabled in response to the first prespecified control signal or the
third prespecified control signal.
35. The apparatus of claim 19, wherein:
the control signals include an address for a determinate repeater; and
a determinate repeater includes means, responsive to the address, for
enabling the means for looping back.
36. The apparatus of claim 19, further including:
second test control means, connected at the second terminal to the second
end of transmission link L.sub.N, for communicating control signals across
the transmission link L.sub.N ; and
wherein each repeater further includes means, responsive to the control
signals on the other transmission link L.sub.i+1, for looping back data
transmitted from the other transmission link L.sub.i+1 for transmission on
the other transmission link L.sub.i+1.
37. An apparatus coupling a first bidirectional transmission link to a
second bidirectional transmission link, comprising:
first means for repeating signals transmitted from the first bidirectional
transmission link for transmission on the second bidirectional
transmission link;
second means for repeating signals transmitted from the second
bidirectional transmission link for transmission on the first
bidirectional transmission link; and
means, responsive to prespecified control signals in-band on the first
bidirectional transmission link, for looping back signals transmitted from
the first bidirectional transmission link for transmission on the first
bidirectional transmission link.
38. The apparatus of claim 37, further including:
means, responsive to prespecified control signals on the second
bidirectional transmission link, for looping back signals transmitted from
the second bidirectional transmission link for transmission on the second
bidirectional transmission link.
39. The apparatus of claim 37, wherein the prespecified control signals
include an address identifYing the apparatus.
40. The apparatus of claim 37, wherein the means for looping back signals
on the first bidirectional link includes:
first loop means, connected to the first means and the second means, for
supplying signals repeated for transmission by the first means to the
second means so that the second means repeats the signals for transmission
on the first bidirectional link.
41. The apparatus of claim 40, wherein the first loop means includes means,
connected between the first means and the second means, for attenuating
the signals repeated by the first means.
42. The apparatus of claim 38, wherein:
the means for looping back signals on the first bidirectional link includes
first loop means, connected to the first means and the second means, for
supplying signals repeated for transmission by the first means to the
second means so that the second means repeats the signals for transmission
on the first bidirectional link; and
wherein the means for looping back signals on the second bidirectional link
includes second loop means, connected to the second means and the first
means, for supplying signals repeated for transmission by the second means
to the first means so that the first means repeats the signals for
transmission on the second bidirectional link.
43. The apparatus of claim 42, wherein:
the first loop means includes means, connected between the first means and
the second means, for attenuating the signals repeated by the first means;
and wherein
the second loop means includes means, connected between the second means
and the first means, for attenuating the signals repeated by the second
means.
44. The apparatus of claim 37, further including:
repeater control means, connected to the first means and the means for
looping back, for generating switching signals in response to prespecified
control signals from the first bidirectional link; and wherein the means
for looping back includes means, responsive to the switching signals, for
connecting the signals on the first bidirectional link for transmission
back on the first bidirectional link.
45. The apparatus of claim 44, wherein the repeater control means comprises
a state machine.
46. The apparatus of claim 45, wherein the repeater control means includes
an internal clock.
47. The apparatus of claim 45, wherein the state machine has more than two
states.
48. The apparatus of claim 38, further including:
repeater control means, connected to the first means, second means, the
means for looping back signals on the first bidirectional link, and the
means for looping back signals on the second bidirectional link, for
generating switching signals in response to prespecified control signals
from the first bidirectional link or the second bidirectional link; and
wherein
the means for looping back signals on the first bidirectional link includes
means, responsive to the switching signals, for connecting the signals on
the first bidirectional link for transmission back on the first
bidirectional link; and wherein
the means for looping back signals on the second bidirectional link
includes means, responsive to the switching signals, for connecting the
signals on the second bidirectional link for transmission back on the
second bidirectional link.
49. The apparatus of claim 48, wherein the repeater control means comprises
a first state machine connected to the means for looping back signals on
the first bidirectional link, and a second state machine connected to the
means for looping back signals on the second bidirectional link.
50. The apparatus of claim 48, wherein the repeater control means comprises
a state machine connected to the means for looping back signals on the
first bidirectional link and to the means for looping back signals on the
second bidirectional link.
51. The apparatus of claim 50, wherein the repeater control means includes
an internal clock.
52. The apparatus of claim 50, wherein the state machine has more than two
states.
53. The apparatus of claim 49, wherein the repeater control means includes
an internal clock.
54. The apparatus of claim 49, wherein the first state machine has more
than two states, and the second state machine has more than two states.
55. The apparatus of claim 37, wherein the prespecified control signals
include a first multibit code, a second multibit code, and a third
multibit code.
56. The apparatus of claim 55, wherein the first multibit code is
010100100, the second multibit code is 001101110, and the third multibit
code is 110001110.
57. An apparatus coupling a first bidirectional T1 transmission link to a
second bidirectional T1 transmission link, comprising:
first means for repeating signals transmitted from the first bidirectional
T1 transmission link for transmission on the second bidirectional T1
transmission link;
second means for repeating signals transmitted from the second
bidirectional T1 transmission link for transmission on the first
bidirectional T1 transmission link; and
means, responsive to prespecified in-band control signals on the first
bidirectional T1 transmission link, for looping back signals transmitted
from the irst bidirectional T1 transmission link for transmission on the
first bidirectional T1 transmission link.
58. The apparatus of claim 57, further including:
means, responsive to prespecified control signals on the second
bidirectional T1 transmission link, for looping back signals transmitted
from the second bidirectional T1 transmission link for transmission on the
second bidirectional T1 transmission link.
59. The apparatus of claim 57, wherein the prespecified control signals
include an address identifying the apparatus.
60. The apparatus of claim 57, wherein the means for looping back signals
on the first bidirectional T1 transmission link includes:
first loop means, connected to the first means and the second means, for
supplying signals repeated for transmission by the first means to the
second means so that the second means repeats the signals for transmission
on the first bidirectional T1 transmission link.
61. The apparatus of claim 60, wherein the first loop means includes means,
connected between the first means and the second means, for attenuating
the signals repeated by the first means.
62. The apparatus of claim 58, wherein:
the means for looping back signals on the first bidirectional T1
transmission link includes,
first loop means, connected to the first means and the second means, for
supplying signals repeated for transmission by the first means to the
second means so that the second means repeats the signals for transmission
on the first bidirectional T1 transmission link; and wherein
the means for looping back signals on the second bidirectional T1
transmission link includes,
second loop means, connected to the second means and the first means, for
supplying signals repeated for transmission by the second means to the
first means so that the first means repeats the signals for transmission
on the second bidirectional T1 transmission link.
63. The apparatus of claim 62, wherein the first loop means includes means,
connected between the first means and the second means, for attenuating
the signals repeated by the first means; and
wherein the second loop means includes means, connected between the second
means and the first means, for attenuating the signals repeated by the
second means.
64. The apparatus of claim 57, further including: repeater control means,
connected to the first means and the means for looping back, for
generating switching signals in response to prespecified control signals
from the first bidirectional T1 transmission link; and wherein the means
for looping back includes means, responsive to the switching signals, for
connecting the signals on the first bidirectional T1 transmission for
transmission back on the first bidirectional T1 transmission link.
65. The apparatus of claim 64, wherein the repeater control means comprises
a state machine.
66. The apparatus of claim 65, wherein the state machine includes a
internal clock.
67. The apparatus of claim 57, wherein the prespecified control signals
include a first multibit code, a second multibit code, and a third
multibit code.
68. The apparatus of claim 67, wherein the first multibit code is
010100100, the second multibit code is 001101110, and the third multibit
code is 110001110.
69. An apparatus coupling a first bidirectional transmission link having an
input channel and an output channel, to a second bidirectional
transmission link having an input channel and an output channel,
comprising:
first means, having a first repeater input and a first repeater output, for
repeating signals supplied to the first repeater input for supplying to
the first repeater output;
second means, having a second repeater input and a second repeater output,
for repeating signals supplied to the second repeater input for supply to
the second repeater output;
first loop means, having a first loop input and a first loop output, for
supplying signals supplied to the first loop input to the first loop
output;
repeater control means, connected to the first repeater output, and
responsive to prespecified control signals, for detecting the prespecified
control signals and generating switch control signals;
first switching means, connected to the repeater control means and
responsive to the switch control signals, for connecting, when indicated
by the switch control signals, the output channel of the first
bidirectional transmission link to the first repeater input and the first
repeater output to the input channel of the second bidirectional
transmission link, and the output channel of the second bidirectional
transmission link to the second repeater input and the second repeater
output to the input channel of the first bidirectional transmission link;
and
second switching means, connected to the repeater control means and
responsive to the switch control signals, for connecting, when indicated
by the switch control signals, the output channel of the first
bidirectional transmission link to the first repeater input and the first
repeater output to the first loop input, and the first loop output to the
second repeater input and the second repeater output to the input channel
of the first bidirectional transmission link.
70. The apparatus of claim 69, wherein the repeater control means is
connected to the second repeater output and further including:
second loop means, having a second loop input and a second loop output, for
supplying signals supplied to the second loop input to the second loop
output; and
third switching means, connected to the repeater control means and
responsive to the switch control signals, for connecting, when indicated
by the switch control signals, the output channel of the second
bidirectional transmission link to the second repeater input and the
second repeater output to the second loop input, and the second loop
output to the first repeater input and the first repeater output to the
input channel of the second bidirectional transmission link.
71. The apparatus of claim 70, wherein the repeater control means includes
means for resolving contention between prespecified control signals
received across the first bidirectional transmission link and prespecified
control signals received across the second bidirectional transmission
link.
72. The apparatus of claim 69, wherein:
the switch control signals indicate a first state, a second state, a third
state, and a fourth state, wherein,
the first state is entered in response to detection of a first prespecified
control signal during the fourth state,
the second state is entered in response to detection of a second
prespecified control signal during the first state,
the third state is entered in response to detection of the second
prespecified control signal during the second state, and
the fourth state is entered in response to detection of a third
prespecified control signal during the third state; and wherein
the first switching means operates during the first state and the fourth
state; and
the second switching means operates during the third state.
73. The apparatus of claim 70, wherein:
the switch control signals indicate a first state, a second state, a third
state, and a fourth state, wherein,
the first state is entered in response to detection of a first prespecified
control signal during the fourth state,
the second state is entered in response to detection of a second
prespecified control signal during the first state,
the third state is entered in response to detection of the second
prespecified control signal during the second state, and
the fourth state is entered in response to detection of a third
prespecified control signal during the third state; and wherein
the first switching means operates during the first state and the fourth
state;
the second switching means operates during the third state if the
prespecified control signals are received across the first bidirectional
transmission link; and
the third switching means operates during the third state if the
prespecified control signals are received across the second bidirectional
transmission link.
74. The apparatus of claim 72, further including:
means, connected to the repeater control means, for generating and
supplying the first prespecified control signal for transmission on the
second bidirectional transmission link during the second state and the
third state; and
wherein in addition, the first state is entered in response to the
detection of the first prespecified control signal at the first repeater
output during the second state.
75. The apparatus of claim 73, further including:
means, having a signal output and connected to the repeater control means,
for generating and supplying the first prespecified control signal at the
signal output during the second state and the third state; and
fourth switching means, connected to the repeater control means and
responsive to the switch control signals, for connecting, when indicated
by the switch control signals, the signal output to the input channel of
the first bidirectional transmission link if the prespecified control
signals are received across the second bidirectional link, or to the input
channel of the second bidirectional transmission link if the prespecified
control signals are received across the first bidirectional link; and
wherein in addition, the first state is entered in response to detection of
the first prespecified control signal from the same bidirectional
transmission link from which the second prespecified signal came during
the second state.
76. The apparatus of claim 73, wherein the repeater control means includes
means for resolving contention between prespecified control signals
received across the first bidirectional transmission link and prespecified
| | |
