1. (canceled)
2. An apparatus comprising:
a comparator operable to receive a first voltage corresponding to a first amount of charge associated with a first source;
a controllable current source coupled to the comparator, the controllable current source operable to provide a current; and
a digital logic circuit coupled to the comparator, the digital logic circuit operable to output, based on a determination that a threshold value for the current is reached, an indication of the first amount of charge.
3. The apparatus of claim 2, wherein the controllable current source is operable to supply the current to the first source and draw the current from the first source, and wherein the digital logic circuit is operable to cause an adjustment to the current supplied to the first source or drawn from the first source.
4. The apparatus of claim 2, wherein the comparator is operable to measure a difference between the first voltage and a second voltage associated with a second source,
wherein the controllable current source is operable to provide the current to the first source based on the difference, and
wherein the digital logic circuit is further operable to:
accumulate a second amount of charge that is proportional to an amount of the current provided by the controllable current source,
determine whether a threshold value for the amount of the current is reached; and
based on determining that the threshold value is reached, output information corresponding to the second amount of charge as the indication of the first amount of charge.
5. The apparatus of claim 4, wherein accumulation of the second amount of charge is based on an amount of time during which the current is provided by the controllable current source.
6. The apparatus of claim 4, wherein determining that the threshold value for the amount of the current is reached comprises determining that the first voltage is within a preselected range of the second voltage.
7. The apparatus of claim 4, wherein the digital logic circuit comprises:
a logic gate that is operable to output a high value in response to the first voltage associated with the first source exceeding the second voltage associated with the second source based on the amount of the current provided to the first source by the controllable current source; and
a control circuit that is operable to control, in response to the high value being output by the logic gate, the controllable current source to thereby cause an adjustment to the amount of the current provided to the first source.
8. The apparatus of claim 7, wherein the digital logic circuit further comprises a digital accumulator that is operable to:
store a value corresponding to the second amount of charge; and
output the stored value in response to the threshold value being reached.
9. The apparatus of claim 8, wherein the digital logic circuit further comprises a compensation circuit, wherein the compensation circuit is operable to:
receive a signal from the control circuit;
in response to a determination of the amount of the current provided to the first source by the controllable current source based on the received signal, compute the second amount of charge that is proportional to the amount of the current provided to the first source by the controllable current source; and
provide information about the second amount of charge to the digital accumulator.
10. The apparatus of claim 9, wherein the compensation circuit is further operable to:
adjust the amount of the current provided to the first source by the controllable current source based on a digital lookup table.
11. The apparatus of claim 7, wherein the digital logic circuit further comprises:
a digital filter that is operable to filter information corresponding to the difference between the first voltage and the second voltage that is output by the comparator; and
a delay circuit that is operable to receive the filtered information from the digital filter and provide a delayed version of the filtered information to the logic gate,
wherein the logic gate is operable to output the high value based on comparing the filtered information received from the digital filter and the delayed version of the filtered information received from the delay circuit.
12. The apparatus of claim 2, wherein the first source includes a capacitor.
13. A method comprising:
receiving, at a comparator, a first voltage corresponding to a first amount of charge associated with a first source;
providing, by a controllable current source coupled to the comparator, a current to the first source; and
outputting, by a digital logic circuit coupled to the comparator, an indication of the first amount of charge based on a determination that a threshold value for the current is reached.
14. The method of claim 13, further comprising:
measuring a difference between the first voltage and a second voltage associated with a second source;
based on measuring the difference, adjusting an amount of the current provided to the first source by the controllable current source;
accumulating a second amount of charge that is proportional to the amount of the current provided to the first source by the controllable current source;
determining whether a threshold value for the amount of the current is reached; and
based on determining that the threshold value is reached, outputting the second amount of charge as the indication of the first amount of charge associated with the first source.
15. The method of claim 14, wherein accumulating the second amount of charge comprises:
accumulating a second amount of charge based on an amount of time during which the current is provided by the controllable current source.
16. The method of claim 14, wherein determining that the threshold value for the amount of the current is reached comprises determining that the first voltage is within a preselected range of the second voltage.
17. The method of claim 14, further comprising:
outputting, by a logic gate, a high value in response to the first voltage associated with the first source exceeding the second voltage associated with the second source based on the amount of the current provided to the first source by the controllable current source; and
in response to the high value being output by the logic gate, controlling, by a control circuit, the controllable current source to thereby cause an adjustment to adjust the amount of the current provided to the first source.
18. The method of claim 17, further comprising:
storing, by a digital accumulator, a value corresponding to the second amount of charge; and
outputting the stored value in response to the threshold value being reached.
19. The method of claim 18, further comprising:
receiving, at a compensation circuit, a signal from the control circuit;
in response to a determination of the amount of the current provided to the first source by the controllable current source based on the received signal, computing the second amount of charge that is proportional to the amount of the current provided to the first source by the controllable current source; and
providing information about the second amount of charge to the digital accumulator.
20. The method of claim 19, further comprising:
adjusting, by the compensation circuit, the amount of the current provided to the first source by the controllable current source based on a digital lookup table.
21. The method of claim 17, further comprising:
filtering, by a digital filter, information corresponding to the difference between the first voltage and the second voltage that is output by the comparator;
in response to receiving the filtered information from the digital filter, providing, by a delay circuit, a delayed version of the filtered information to the logic gate; and
outputting, by the logic gate, the high value based on comparing the filtered information received from the digital filter and the delayed version of the filtered information received from the delay circuit.
22. The method of claim 13, wherein the first source includes a capacitor.
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 assigning a mobile subscriber roaming number, wherein in a Visitor Location Register, the mobile subscriber roaming number is managed by a plurality of Visitor Location Register modules, characterized in that: said mobile subscriber roaming number comprises a Visitor Location Register module number, and said Visitor Location Register module number is utilized to directly determine the correspondence relationship between said assigned mobile subscriber roaming number and the Visitor Location Register module in said Visitor Location Register that manages said mobile subscriber roaming number.
2. The method according to claim 1, characterized in that, said method comprising the following steps:
said Visitor Location Register receives from a Home Location Register a request to assign a roaming number for a mobile subscriber;
said Visitor Location Register forwards the request to one of the Visitor Location Register modules;
said Visitor Location Register module records the information corresponding to said mobile subscriber and obtains its corresponding VLR sub-number;
said Visitor Location Register module generates a mobile subscriber roaming number, said mobile subscriber roaming number comprises a country code, the number of a Mobile Switching Center where said mobile subscriber is in, the module number of said Visitor Location Register module, said VLR sub-number;
said Visitor Location Register module returns said mobile subscriber roaming number to said Home Location Register.
3. The method according to claim 2, characterized in that, said recording step further comprising:
said Visitor Location Register module records the information of said mobile subscriber in an idle record in a mobile subscriber roaming number information table, and obtains the VLR sub-number corresponding to said record.
4. The method according to claim 1, characterized in that, said Visitor Location Register is a multi-module-clustered distributed real time database.
5. The method according to claim 1, characterized in that, the length of the module number of said Visitor Location Register module may be one bit or multiple bits.
6. The method according to claim 1, characterized in that, the length of said mobile subscriber roaming number is not longer than 15 bits.
7. A method for searching a mobile subscriber roaming number, wherein in a Visitor Location Register, the mobile subscriber roaming number is managed by a plurality of Visitor Location Register modules, characterized in that, said mobile subscriber roaming number comprises a Visitor Location Register module number, and said Visitor Location Register module number is utilized to directly find the Visitor Location Register module in said Visitor Location Register that manages said mobile subscriber roaming number, thereby obtains the information of said mobile subscriber.
8. The method according to claim 7, characterized in that, said method comprising the following steps:
based on said mobile subscriber roaming number, a Visitor Mobile Switching Center initiates a query to the Visitor Location Register module corresponding to said mobile subscriber roaming number;
said Visitor Location Register module searches the information of corresponding mobile subscriber based on said mobile subscriber roaming number, and returns it to said Visitor Mobile Switching Center.
9. The method according to claim 8, characterized in that, said step of initiating a query further comprising:
said Visitor Mobile Switching Center decomposes said mobile subscriber roaming number into a country code, a Mobile Switching Center number and a Visitor Location Register module number based on the assignment format of said mobile subscriber roaming number;
said Visitor Mobile Switching Center sends the query request to the Visitor Location Register module corresponded to said Visitor Location Register module number.
10. The method according to claim 8, characterized in that, said searching step further comprising:
said Visitor Location Register module obtains the VLR sub-number in said mobile subscriber roaming number, and obtains the information of said mobile subscriber in the record of the mobile subscriber roaming number information table corresponded to said VLR sub-number, and returns it to said Visitor Mobile Switching Center;
said Visitor Location Register module releases said VLR sub-number.