What is claimed is:
1. An apparatus for switching a GPRS (General Packet Radio Service) service class in a GPRS terminal, comprising:
a temperature sensor for measuring a temperature of at least one specific element in the GPRS terminal during a GPRS mode of operation;
a limit data register for storing a critical temperature of the at least one specific element for the GPRS service class; and
a controller for comparing the measured temperature from the temperature sensor with the critical temperature stored in the limit data register, and switching the GPRS service class from a first class to a second class when the measured temperature is greater than or equal to the critical temperature.
2. The apparatus as claimed in claim 1, wherein the controller maintains the present GPRS service class when the measured temperature is less than the critical temperature.
3. The apparatus as claimed in claim 1, wherein the controller switches the GPRS service class from the first class back to the second class when the measured temperature becomes less than the critical temperature during the second class GPRS service.
4. The apparatus as claimed in claim 1, further comprising an analog-to-digital (AD) converter for converting an analog value of the temperature measured by the temperature sensor to a digital value.
5. A method for switching a GPRS (General Packet Radio Service) service class according to generated heat in a GPRS terminal, comprising the steps of:
measuring a temperature of at least one specific element in the GPRS terminal during a GPRS mode of operation;
determining to switch the GPRS service class from a first class to a second class when the measured temperature is greater than or equal to a critical temperature;
sending a request for switching the GPRS service class to the second class to a base station through an uplink; and
upon receipt of a service class-down switch command from the base station through a downlink in response to the GPRS service class switch request, switching the GPRS service class to the second class.
6. The method as claimed in claim 5, further comprising the step of maintaining the present GPRS service class when the measured temperature is less than the critical temperature.
7. The method as claimed in claim 5, further comprising the steps of:
determining to switch the GPRS service class back to the first class when the measured temperature becomes less than the critical temperature during the second class GPRS service;
sending a request for switching the GPRS service class to the first class to the base station through the uplink; and
upon receipt of a service class-up switch command from the base station through a downlink in response to the GPRS service class switch request, switching the GPRS service class to the first class.
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 of manufacture of a ventilation chimney section comprising welding plastic sheets to form inner and outer cylindrical tubes placing said inner tube within said outer tube and sliding a sheet of insulation between said inner and outer tube.
2. Method of claim 1 where said sheet of insulation is cut into a plurality of segments, alignable parallel to the common axis of said tubes, before sliding said sheet between said inner and outer tubes.
3. Method of claim 2 where said sheet of insulation is cut into four quarter cylindrical segments, alignable parallel to the common axis of said tubes.
4. Method of claim 1 where said sheet fits snugly between said inner and outer tubes.
5. Method of claim 4 where said sheet of insulation is cut into a plurality of segments, alignable parallel to the common axis of said tubes, before sliding said sheet between said inner and outer tubes.
6. Method of claim 5 where said sheet of insulation is cut into four quarter cylindrical segments, alignable parallel to the common axis of said tubes.
7. Method of claim 1 where the collar of a male coupling element is inserted into one end of said section between said inner and outer tubes and secured therein, and the collar of a female coupling element is inserted into the other end of said section between said inner and outer tubes and secured therein, said male coupling element being adapted to matingly engage a female coupling identical to said female coupling element and vice versa.
8. Method of claim 7, where said collars are secured between said inner and outer tubes by fasteners.
9. Method of claim 8, wherein said fasteners are screws extending through said outer tube and into said collars.
10. Chimney ventilation section comprising coaxial inner and outer plastic tubes separated by a sheet of insulation in the space between said inner and outer tubes.
11. Section of claim 10 wherein said sheet of insulation fits snugly between said inner and outer tubes.
12. Section of claim 11 wherein said sheet of insulation has four quarter cylindrical segments aligned parallel to the common axis of said tubes.
13. Section of claim 10 where the collar of a male coupling element is inserted into one end of said section between said inner and outer tubes and secured therein, and the collar of a female coupling element is inserted into the other end of said section between said inner and outer tubes and secured therein, said male coupling element being adapted to matingly engage a female coupling identical to said female coupling element and vice versa.
14. Section of claim 13, where said collars are secured between said inner and outer tubes by fasteners.
15. Section of claim 14, wherein said fasteners are screws extending through said outer tube and into said collars.
16. Section of claim 14, wherein said male coupling element has a first circumferential wall abutting the collar of said male coupling element projecting outward, a first inner cylindrical sleeve at the inner edge of said first circumferential wall said first sleeve forming a plug to engage a socket of a female coupling element.
17. Section of claim 14 wherein said female coupling element has a second circumferential wall abutting said collar projecting outward, and a second outer cylindrical sleeve at the outer edge of said circumferential wail, said second sleeve and said second wall forming a socket to engage a plug of a male coupling element.