Sprint Communications Comapny L.p.

Steven Kenneth Guthrie

Timothy Hugh Pearson

Roger Danforth Bartlett

John Austin Holmes

David Richard Polson

Seng Chai Gan

James Walter Norris

Adeel Ahmed Siddiqui

Christian Erik Seagren

Methods and systems are provided for enabling a base station to receive signals and synchronization information from neighboring base stations over a frequency band designated for transmissions to mobile devices. In embodiments, a cancellation signal is used to cancel antenna overload resulting from a base station's own transmission. By negating antenna overload, the base station may listen for synchronization signals output by neighboring base stations over the frequency band designated for transmission to mobile devices, such as a downlink band, for example. In embodiments, synchronization signals are used by the base station and/or a server to detect when synchronization failures occur at the base station and/or neighboring base stations. Synchronization signals from a neighboring base station may be used to re-synchronize a base station that have experience such a failure, in some embodiments.

Detection of base station synchronization failure

A method and system are provided for converting an enhanced Long Range Navigational (eLORAN) signal to a Precision Time Protocol (PTP) signal. Network devices can be located within buildings and not have access to a GPS signal directly from a GPS satellite. Network devices may also be located in a line of sight of a GPS satellite but may lose the GPS signal. An adapter is provided that takes an eLORAN signal, when a GPS signal is lost or not available, and converts the signal into a PTP and other signals to act as timing, synchronization, and syntonization inputs into the network devices. In some cases, the network devices can have a PTP client to receive the PTP signal, one pulse per second signal, and a ten (10) megahertz frequency signal. In other cases, the network devices do not have a PTP client, but can receive a time of day message, one pulse per second signal, and the 10 megahertz frequency signal.

Adapter that converts enhanced long range navigation (eLORAN) to precision time protocol (PTP)

The invention is directed to methods and systems for generating reference signals from radio signals received from a large-coverage access component, such as a base station. The radio signals are received, analyzed, and selected based on the analysis. The selected signals are processed by an oscillator to filter out abnormalities. Consequently, a reference signal is generated that is encapsulated into packets and delivered to one or more small-coverage access components using the Precision Timing Protocol or some other protocol that is useable by the small-coverage access components. The small-coverage access components comprise one or more of a femtocell or a picocell.

Generating reference signals from selected signals

Methods and systems are provided for enabling a base station to listen and receive signals from neighboring base stations over a frequency designated for transmission to mobile devices for the detection of a synchronization failure. Embodiments provided herein enable the base station to cancel out its own transmission signal(s), which overloads the base station's own antennadue to proximity. By cancelling out the base station's own signal, the base station listens and receives synchronization signals from one or more neighboring base stations over the frequency designated for transmission in a wireless communications network. A synchronization signal may be used, by the base station or as relayed to a server, to determine if the base station or the neighboring base station has experienced a synchronization failure.

Methods and systems are provided for detecting a synchronization failure of a base station in a wireless communications network. A server receives synchronization data, such as a phase offset between two base stations, from one or more base stations. A difference between each of the synchronization data and the corresponding control data is computed to determine if one or more of the differences is outside a predetermined threshold. If so, the base station that has the synchronization failure is identified.

Methods, media, and systems are provided for characterizing the synchronization behavior of a slave clock. A sequence of sync packets, usable to synchronize with a grandmaster clock, is transmitted from the grandmaster clock to a slave clock. The sequence of sync packets is modified by dropping one or more sync packets from the sequence, providing a pattern of dropped sync packets. A synchronization output of the slave clock is monitored and, based on the synchronization output, a determination is made as to whether the slave clock is synchronized while the sequence of sync packets is modified. A characterization of the synchronization behavior of the slave clock is stored with respect to the pattern of dropped sync packets. The process may be repeated for various patterns of dropped sync packets.

Characterizing slave clock synchronization behavior by means of dropped sync packets

The invention is directed to methods and systems for generating frequency reference signals from a radio signal received from a large-coverage access component, such as a base station. The radio signal is received and processed by an oscillator to filter out abnormalities. Consequently, a frequency reference signal is generated that is encapsulated into packets and delivered to one or more small-coverage access components using the Precision Timing Protocol or some other protocol that is useable by the small-coverage access components. The small-coverage access components comprise one or more of a femtocell or a picocell.

Generating frequency reference signals

Systems, methods, and computer-readable media for adding and removing unanchored small cell sites for a cluster that delivers precision time protocol frequency and phase synchronization over a network without on-path support are provided. In embodiments, the method includes continuously measuring, in an asymmetric network without on-path support, an anchor path delay. A maximum standard allowable (MSA) delay variation is determined for the cluster. A respective round trip (RT) delay is continuously measured from the host site to each unanchored small cell site in the cluster. The anchor path delay is compared to each respective RT delay to determine a respective unanchored delay variation. In embodiments, unanchored small cell sites are be added to or removed from the cluster based on a comparison of a respective unanchored delay variation to the MSA delay variation.

Method of adding and removing sites for a cluster based on a baseline delay comparison

Systems, methods, and computer-readable media for improving accuracy for providing precision time protocol (PTP) frequency and phase synchronization to each unanchored small cell site in a cluster over non on-path supported networks are provided. In embodiments, the method includes continuously measuring one-way delay down (OWDd) and delay offset down from a host site to an anchored site and one-way delay up (OWDu) and delay offset up from the anchored site to the host site. Round trip (RT) delay from the host site to each unanchored site is continuously measured. A one-way delay down prime (OWDd') is determined for each unanchored site by applying the ratio of OWDu/OWDd to the corresponding RT delay for each unanchored small cell site. An adjusted dynamic corrective offset (DCO) is determined for each unanchored site by adding the respective OWDd&#x2032; to the respective time stamp and the delay offset down.

Increasing accuracy for delivering precision time protocol frequency and phase synchronization over a network without on-path support

Systems, methods, and computer-readable media for precision time protocol (PTP) frequency and phase synchronization to unanchored sites over non on-path supported networks are provided. In embodiments, the method includes continuously measuring one-way delay (OWD) and delay offset from a host site to an anchored site to determine a dynamic corrective offset (DCO). One of a plurality of unanchored sites is identified. In embodiments, the DCO is applied to PTP sync or PTP follow-up messages communicated from the host site to the identified unanchored site. The clocks associated with the unanchored sites are synchronized to the host clock.

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Kansas City, MO, United States of America

Steven Kenneth Guthrie