Transmission level point: Difference between revisions
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The [[dBm]] is an absolute reference level measurement (see {{Slink|Decibel|Suffixes and reference values}}) with respect to 1 mW power. When the nominal signal power is {{gaps|0|dBm}} at the TLP, the test point is called a ''zero transmission level point'', or ''zero-dBm TLP''. The abbreviation [[dBm0]] stands for the power in [[dBm]] measured at a zero transmission level point. The TLP is thus characterized by the relation:<ref name="reeve" /> | The [[dBm]] is an absolute reference level measurement (see {{Slink|Decibel|Suffixes and reference values}}) with respect to 1 mW power. When the nominal signal power is {{gaps|0|dBm}} at the TLP, the test point is called a ''zero transmission level point'', or ''zero-dBm TLP''. The abbreviation [[dBm0]] stands for the power in [[dBm]] measured at a zero transmission level point. The TLP is thus characterized by the relation:<ref name="reeve" /> | ||
:TLP = dBm | :TLP = dBm − dBm0 | ||
The term ''TLP'' is commonly used as if it were a unit,<ref name="tia"/> preceded by the nominal level for the test point. For example, the expression ''{{gaps|0|TLP}}'' refers to a ''{{gaps|0|dBm|TLP}}''. If for instance a signal is specified as -13 dBm0 at a particular point and -6 dBm is measured at that point, the TLP is +7 TLP.<ref>{{Cite web |last=Reeve |first=Whitham D. |date=1996 |title=Application Note No. 8 |url=https://reeve.com/Documents/Transmission%20Level%20Point%20No8.pdf |url-status=live |archive-url=https://web.archive.org/web/20230201062929/https://reeve.com/Documents/Transmission%20Level%20Point%20No8.pdf |archive-date=2023-02-01 |access-date=2023-06-26 |website=reeve.com}}</ref> | The term ''TLP'' is commonly used as if it were a unit,<ref name="tia"/> preceded by the nominal level for the test point. For example, the expression ''{{gaps|0|TLP}}'' refers to a ''{{gaps|0|dBm|TLP}}''. If for instance a signal is specified as -13 dBm0 at a particular point and -6 dBm is measured at that point, the TLP is +7 TLP.<ref>{{Cite web |last=Reeve |first=Whitham D. |date=1996 |title=Application Note No. 8 |url=https://reeve.com/Documents/Transmission%20Level%20Point%20No8.pdf |url-status=live |archive-url=https://web.archive.org/web/20230201062929/https://reeve.com/Documents/Transmission%20Level%20Point%20No8.pdf |archive-date=2023-02-01 |access-date=2023-06-26 |website=reeve.com}}</ref> | ||
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*[https://link.springer.com/referenceworkentry/10.1007/1-4020-0613-6_21341 Zero transmission level point] | *[https://link.springer.com/referenceworkentry/10.1007/1-4020-0613-6_21341 Zero transmission level point] | ||
[[Category:Telecommunications engineering]] | |||
{{telecom-stub}} | |||
Latest revision as of 14:51, 24 September 2025
In telecommunications, a transmission level point (TLP) is a test point in an electronic circuit that is typically a transmission channel. At the TLP, a test signal may be introduced or measured.[1] Various parameters, such as the power of the signal, noise, voltage levels, wave forms, may be measured at the TLP.[2]
The nominal transmission level at a TLP is a function of system design and is an expression of the design gain or attenuation (loss).
Voice-channel transmission levels at test points are measured in decibel-milliwatts (dBm) at a frequency of ~1000 hertz.
The dBm is an absolute reference level measurement (see Template:Slink) with respect to 1 mW power. When the nominal signal power is Template:Gaps at the TLP, the test point is called a zero transmission level point, or zero-dBm TLP. The abbreviation dBm0 stands for the power in dBm measured at a zero transmission level point. The TLP is thus characterized by the relation:[1]
- TLP = dBm − dBm0
The term TLP is commonly used as if it were a unit,[2] preceded by the nominal level for the test point. For example, the expression Template:Gaps refers to a Template:Gaps. If for instance a signal is specified as -13 dBm0 at a particular point and -6 dBm is measured at that point, the TLP is +7 TLP.[3]
The level at a TLP where an end instrument, such as a telephone set, is connected is usually specified as Template:Gaps.