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AUTOMATIC HIGH STABILITY FREQUENCY REFERENCE PERFORMANCE SIGNALING

IP.com Disclosure Number: IPCOM000008343D
Original Publication Date: 1997-Sep-01
Included in the Prior Art Database: 2002-Jun-07
Document File: 2 page(s) / 75K

Publishing Venue

Motorola

Related People

James Gehrke: AUTHOR [+2]

Abstract

Modem wireless communications base stations often require an external high stability frequency reference to meet regulatory requirements. In the USA and other markets, there are two distinct levels of performance required. The difference between the two has a major impact on the cost of the exter- nal frequency reference. This makes it desirable to have multiple stability options.

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MO7VROLA Technical Developments

AUTOMATIC HIGH STABILITY FREQUENCY REFERENCE PERFORMANCE SIGNALING

by James Gehrke and Peter P. Walter

BACKGROUND

  Modem wireless communications base stations often require an external high stability frequency reference to meet regulatory requirements. In the USA and other markets, there are two distinct levels of performance required. The difference between the two has a major impact on the cost of the exter- nal frequency reference. This makes it desirable to have multiple stability options.

  There is potential problem when we can connect a single site frequency reference to a large number of base stations. Namely, the operators must be certain each station is connected to a site frequency reference that has a frequency stability that meets the regulatory requirements.

  A method is needed to signal the frequency stability of the site frequency reference to the base station. Then the base station can determine if the regulatory frequency stability requirements for its operation are fulfilled. This new approach solves

the problem (without any additional cabling) by using the output frequency to indicate frequency stability. This protocol in combination with the ability of the base station reference synthesizer to lock to different frequencies makes an automatic method of detecting a stability problem possible.

PRINCIPLE OF OPERATION

  The lower (better than 0.5 PPM for example) stability reference will output a 10 MHz signal while t...