Topic
Jam sync
About: Jam sync is a research topic. Over the lifetime, 126 publications have been published within this topic receiving 1611 citations.
Papers published on a yearly basis
Papers
Patent•
7 Nov 1996TL;DR: In this paper, a magnetic disk storage system is disclosed wherein byte synchronization to sector data is achieved even when noise in the read channel, due for instance to a thermal asperity (TA), corrupts the primary preamble and/or sync mark fields or causes a loss of frequency or phase lock.
Abstract: A magnetic disk storage system is disclosed wherein byte synchronization to sector data is achieved even when noise in the read channel, due for instance to a thermal asperity (TA), corrupts the primary preamble and/or sync mark fields or causes a loss of frequency or phase lock. The data sector format is modified to comprise at least one secondary sync mark in addition to the conventional primary sync mark recorded at the beginning of the data field. In this manner, when the primary sync mark becomes undetectable due to errors, or when byte synchronization is lost, the storage system can still synchronize to the data sector using the secondary sync mark. The secondary sync mark is preferably spaced apart from the primary sync mark with either a gap (no data) or user data inserted inbetween. In the latter embodiment, two methods are employed to recover user data inbetween the primary and secondary sync marks when the primary sync mark is undetectable: on-the-fly erasure pointer error correction, and buffering to facilitate retroactive synchronization. The secondary sync mark may optionally include a secondary preamble to facilitate phase locking to the data when the primary preamble is corrupted by errors. The present invention also provides "split segment" resynchronization for synchronizing a first section of data using a first mark, and retroactively synchronizing a second section of data using a following sync mark when synchronization is lost.
141 citations
Patent•
12 Jun 2001
TL;DR: In this paper, the authors present a system for synchronizing a device and ensuring that updates to the device occurring during synchronization are not re-synchronized to the synchronization partner.
Abstract: Systems and methods for synchronizing a device and for ensuring that updates to the device occurring during synchronization are not re-synchronized to the synchronization partner. Generation identifiers (GIDs), which are updated each time a synchronization occurs, are assigned to objects in a store. When synchronization occurs, a sync client uses state information, which is used to indicate which generations have been synchronized, to determine which objects have changed since the last synchronization. The state information includes reserved write GIDs that are only used by a particular sync client that performs writes during a synchronization. Objects having a GID that matches a write GID are not synchronized because they were written by the sync client during the previous synchronization.
109 citations
Patent•
1 Feb 2002TL;DR: In this paper, a soft delete request is made to the wireless device, which does not meet parameters of a synchronization filter, and if none of the other device sync modules protest, the object is deleted.
Abstract: Systems, methods, and computer program products for deleting objects from device stores without deleting corresponding objects from one or more synchronization partners. A device has a device sync module for each synchronization partner and each device sync module maintains tracking data. Alternatively, a single device sync module manages the tracking data of each synchronization partner. When an object does not meet parameters of a synchronization filter, a soft delete request is made to the wireless device. A sync manager receives the soft delete request and determines from the other device sync modules that have registered with the sync manager whether they continue to synchronize the object. If none of the other device sync modules protest, the object is deleted. If one of the device sync modules objects to the delete request, then the delete is denied. The tracking data for all of the device sync modules is appropriately modified.
86 citations
Patent•
29 Apr 2000TL;DR: In this article, the primary sync code is acquired at the starting point of a frame and the frame is equal to one period of a spreading code, and the secondary sync codes are assigned to base station groups, one to a group.
Abstract: A synchronization (sync) code communication device for an CDMA communication system. A base station sync code transmission device comprises a primary sync code transmitter and a secondary sync code transmitter. The primary sync code transmitter is for generating and then transmitting a primary sync code at a first location in a transmission frame. The primary sync code is for acquiring synchronization at a starting point of a frame and the frame is equal to one period of a spreading code. The secondary sync code transmitter is for generating and then transmitting a secondary sync code at a second location in a frame. The secondary sync codes are assigned to base station groups, one to a group. A mobile station sync code receiving device comprises a primary sync code acquisition decider and a base station group decider.; The primary sync code acquisition decider is for acquiring a primary sync code received at a first location in a frame, and then acquiring synchronization at a starting point of a frame. The base station group decider is enabled upon acquisition of the primary sync code, receives a secondary sync code transmitted at a second location in the frame, and then determines the base station group to which the transmitting base station belongs.
66 citations
Patent•
IBM1
TL;DR: In this article, the authors present a system, method and data format wherein a redundant sync byte or group of sync bytes is provided in a data sector at a distance sufficient to isolate the redundant sync bytes from the primary sync byte in the event of multiple byte defects.
Abstract: The present invention provides a system, method and data format wherein a redundant sync byte or group of sync bytes is provided in a data sector at a distance sufficient to isolate the redundant sync byte from the primary sync byte in the event of multiple byte defects. In a first embodiment, a redundant sync byte, or group of sync bytes, is provided in the AGC field preceding the primary sync region. Upon failure to detect the primary sync byte, an attempt is made on a subsequent revolution to read the secondary sync byte, either by holding the AGC gain prior to reaching the data block, or initiating an “early read” just prior to reaching the data block. In a second embodiment of the invention, the redundant sync byte is provided within the data field subsequent to the primary sync region. On failing to detect the primary sync byte, the secondary sync byte can be read immediately or can be postponed until a subsequent revolution. The missed first data region is reconstructed using ECC information. In third and fourth alternative embodiments, a secondary sync byte is provided either between the primary sync byte and the start of data or between the primary sync byte and AGC field.
61 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2015 | 1 |
| 2014 | 2 |
| 2013 | 4 |
| 2012 | 3 |
| 2011 | 1 |
| 2008 | 2 |