1. A circuit arrangement for producing a dual-rail output signal comprising:
a first input with at least two connections for receiving a dual-rail input signal;
a second input for receiving a control signal;
a signal processing apparatus having a first switch and a second switch, which are each driven as a function of the input signal, and having two outputs, wherein the first output of the signal processing apparatus is connected via one of the switches to a foot point, which is at a first potential, of the signal processing apparatus, and the second output of the signal processing apparatus is connected via the other switch to the foot;
a switching apparatus, having two inputs, which are connected to the respective outputs of the signal processing apparatus, and two outputs which are connected to two respective outputs of the circuit arrangement in order to output a dual-rail output signal, wherein the outputs of the switching apparatus are each connected to one or both of the inputs of the switching apparatus as a function of the control signal; and
a potential monitoring apparatus for defining the potentials at the outputs of the circuit arrangement when the outputs of the circuit arrangement are not connected via the switching apparatus and the signal processing apparatus to the foot of the signal processing apparatus.
2. The circuit arrangement as claimed in claim 1, wherein the switching apparatus is designed to allow the following operating situations:
E1 connected to D1 and E2 connected to D2: z=not (f(a));
E1 connected to D2 and E2 connected to D1: z=f(a);
E1 connected to D1 and D2, E2 open: z=0; and
E2 connected to D1 and D2, E1 open: z=1,
wherein E1 and E2 are the respective outputs of the switching apparatus, D1 and D2 are the respective inputs of the switching apparatus, z is the dual-rail output signal, and f(a) is a function of the dual-rail input signal.
3. The circuit arrangement as claimed in claim 1, further comprising a precharge apparatus, which is driven by a precharge signal and which produces a predetermined identical potential, before each transmitted data item, at the circuit arrangement outputs which carry data.
4. The circuit arrangement as claimed in claim 1, wherein a third switch driven by the precharge signal is arranged in series with the signal processing apparatus and the switching apparatus, in order to prevent a direct connection between the first potential and the second potential via the first and second switches of the signal processing apparatus and switches of the switching apparatus.
5. The circuit arrangement as claimed in claim 1, wherein the signal processing apparatus contains a switching network via which an XOR function is implemented.
6. A method for producing a dual-rail output signal on first and second associated data lines, comprising the steps of:
providing a first switch, which is controlled by a first signal {circumflex over (f)}(a, aq), and a second switch, which is controlled by a second signal {circumflex over (f)}q(a, aq), where a, aq is a dual-rail data input signal, wherein {circumflex over (f)}q(a)=not (f(a)) for a valid data signal for which aq=not (a);
connecting the data lines to the first and second switches in one of the following combinations:
the first data line to the first switch and the second data line to the second switch; or
the first data line to the second switch and the second data line to the first switch; or
the first data line to the first switch and to the second switch and the second data line neither to the first switch nor to the second switch; or
the second data line to the first switch and the second switch, and the first data line neither to the first switch nor to the second switch; and
wherein, when one of the first and second switches is closed, the data line which is connected to the closed switch is brought to a first potential, and wherein a second potential is associated with the other of the first and second data lines.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for generating reliability tests for telephone systems, comprising:
generating an orthogonal array which includes test cases having combinations of test parameters;
obtaining call characteristics from field data based upon actual telephone usage;
obtaining probabilistic weights for different call characteristics based upon a frequency of occurrence in the field data;
using the probabilistic weights to select desirable test cases from the orthogonal array;
running tests on the telephone system using the selected desirable test cases;
collecting test data from the tests that have been run; and
calculating reliability metrics for the telephone system based on the test data.
2. The method according to claim 1 wherein the tests are run using automated test scripts.
3. The method according to claim 2 wherein the orthogonal array is generated using the Taguchi method.
4. The method according to claim 3 wherein the orthogonal array includes tests cases which include at least call types, scenarios, and durations.
5. The method according to claim 4 wherein the call types are selected from the group including a transfer, point-to-point, hold, conference, and others.
6. The method according to claim 5 wherein the test scripts are run for the different call types.
7. The method according to claim 1 wherein the reliability metrics are selected from the group including at least a mean time to failure, a mean time to failure with a predetermined confidence factor, the probability that a telephone will fail after a certain time period, and the probability that a telephone will survive for a certain time period.
8. The method according to claim 4 wherein the test cases of the orthogonal array are divided into groups by common characteristics and wherein a test case is randomly selected from one of the groups once the group is selected based upon its probabilistic weight as determined from the field data.
9. A computer program on a computer readable medium that generates reliability tests for telephone systems, comprising:
generating an orthogonal array which includes test cases having combinations of test parameters;
obtaining call characteristics from field data based upon actual telephone usage;
obtaining probabilistic weights for different call characteristics based upon a frequency of occurrence in the field data;
using the probabilistic weights to select desirable test cases from the orthogonal array;
running tests on the telephone system using the selected desirable test cases;
collecting test data from the tests that have been run; and
calculating reliability metrics for the telephone system based on the test data.
10. The computer program according to claim 9 wherein the tests are run using automated test scripts.
11. The computer program according to claim 10 wherein the orthogonal array is generated using the Taguchi method.
12. The computer program according to claim 11 wherein the orthogonal array includes tests cases which include at least call types, scenarios, and durations.
13. The computer program according to claim 12 wherein the call types are selected from the group including a transfer, p2p, hold, and conference.
14. The computer program according to claim 13 wherein the test scripts are run for the different call types.
15. The computer program according to claim 9 wherein the reliability metrics are selected from the group including at least a mean time to failure, a mean time to failure with a predetermined confidence factor, the probability that a telephone will fail after a certain time period, and the probability that a telephone will survive for a certain time period.
16. The computer program according to claim 12 wherein the test cases of the orthogonal array are divided into groups by common characteristics and wherein a test case is randomly selected from one of the groups once the group is selected based upon its probabilistic weight as determined from the field data.
17. A method for generating reliability tests for communication systems, comprising:
generating an orthogonal array which includes test cases having combinations of test parameters;
obtaining operational characteristics from field data based upon actual communication usage;
obtaining probabilistic weights for different operational characteristics based upon a frequency of occurrence in the field data;
using the probabilistic weights to select desirable test cases from the orthogonal array;
running tests on the communication system using the selected desirable test cases;
collecting test data from the tests that have been run; and
calculating reliability metrics for the communication system based on the test data.
18. The method according to claim 17 wherein the tests are run using automated test scripts.
19. The method according to claim 18 wherein the orthogonal array is generated using the Taguchi method.
20. The method according to claim 19 wherein the orthogonal array includes tests cases which include at least operational types, scenarios, and durations.
21. The method according to claim 20 wherein the test scripts are run for the different operational types.
22. The method according to claim 17 wherein the reliability metrics are selected from the group including at least a mean time to failure, a mean time to failure with a predetermined confidence factor, the probability that a communication will fail after a certain time period, and the probability that a communication device will survive for a certain time period.
23. The method according to claim 20 wherein the test cases of the orthogonal array are divided into groups by common characteristics and wherein a test case is randomly selected from one of the groups once the group is selected based upon its probabilistic weight as determined from the field data.
24. A computer program on a computer readable medium that generates reliability tests for communication systems, comprising:
generating an orthogonal array which includes test cases having combinations of test parameters;
obtaining operational characteristics from field data based upon actual communication usage;
obtaining probabilistic weights for different operational characteristics based upon a frequency of occurrence in the field data;
using the probabilistic weights to select desirable test cases from the orthogonal array;
running tests on the communication system using the selected desirable test cases;
collecting test data from the tests that have been run; and
calculating reliability metrics for the communication system based on the test data.
25. The computer program according to claim 24 wherein the tests are run using automated test scripts.
26. The computer program according to claim 25 wherein the orthogonal array is generated using the Taguchi method.
27. The computer program according to claim 26 wherein the orthogonal array includes tests cases which include at least operational types, scenarios, and durations.
28. The computer program according to claim 27 wherein the test scripts are run for the different operational types.
29. The computer program according to claim 26 wherein the reliability metrics are selected from the group including at least a mean time to failure, a mean time to failure with a predetermined confidence factor, the probability that a communication device will fail after a certain time period, and the probability that a communication device will survive for a certain time period.
30. The computer program according to claim 27 wherein the test cases of the orthogonal array are divided into groups by common characteristics and wherein a test case is randomly selected from one of the groups once the group is selected based upon its probabilistic weight as determined from the field data.