Redundant path communication methods and systems

A method for communicating using a primary link and a redundant link, wherein data transmitted via the primary link and the redundant link are substantially the same, the method comprising:

• receiving a first data packet in the form of a first protocol;
• formatting the first data packet for transmission in a frame that utilizes a second protocol different than the first protocol, the second protocol utilizing frame identifiers;
• transmitting the formatted first data packet to a second transceiver along a primary link;
• transmitting the formatted first data packet to a third transceiver along a first leg of a redundant link;
• transmitting the formatted first data packet to a fourth transceiver along a second leg of the redundant link;
• transmitting the formatted first data packet to the second transceiver along a third leg of the redundant link;
• storing a portion of the data packet that is received via the primary link at the second transceiver until the first data packet received via the redundant link is received by the second transceiver;
• determining an error rate for the first data packet that was received via the primary link;
• selecting either the first data packet that was received via the primary link or the first data packet that was received via the redundant link based on the error rate;
• and
• transmitting the selected first data packet using the first protocol;
• wherein the primary link is a free space optical link.

A communication system configured to communicate using a primary link and a redundant link, wherein packets transmitted via the primary link and the redundant link are substantially the same, the system comprising:

• a first transceiver configured to transmit a series of first packets over a primary link and forward a series of second packets which corresponds to the first series of packets over a first cross-connect;
• a second transceiver configured to receive the second series of packets via the first cross-connect and transmit the second series of packets over the redundant link;
• a third transceiver configured to receive the second series of packets via the redundant link and transmit the second series of packets over a second cross-connect;
• a fourth transceiver configured to receive the first series of packets and the second series of packets and determine a quality for the first and second series of packets;
• a first buffer in communication with the fourth transceiver and configured to store a portion of the first series of packets;
• a second buffer in communication with the fourth transceiver and configured to store a portion of the second series of packets;
• a link controller module in communication with the first and second buffers and configured to select packets from the first buffer and the second buffer;
• wherein the primary link is a free space optical link.

A transceiver configured to receive and transmit data packets over a free space optical link, a cross-connect, and an external network, the transceiver comprising:

• a payload module configured to adapt a data packet for transmission on an internal network and on the external network, wherein the internal network and the external network employ different transmission protocols;
• a cross-connect module configured to communicate the data packet between the transceiver and a standby transceiver;
• a free space optical module configured to adapt the data packet for its transmission and reception as an optical signal;
• and
• a logic device configured to determine a quality of an incoming data packet from the free space optical link, and configured to select between the data packet received from the free space optical module and from the data packet received from the cross-connect link based on the quality.

A method for performing a read process by a transceiver in a redundant path communication system, the transceiver comprising a port A and a port B, the transceiver receiving a first series of data packets via a primary link into the port A, and the transceiver receiving a second series of data packets via a redundant link, the first and second series of packets being substantially the same, the method comprising:

• setting a location pointer to a first valid buffer location on the port A;
• reading the first valid buffer location on the port A;
• forwarding the first valid buffer location on the port A to an output controller;
• setting a first mailbox bit associated with the first valid buffer location on the port A to invalid;
• setting a second mailbox bit for a second buffer in the port B to invalid, the second mailbox bit corresponding to the first mailbox bit;
• selecting a next buffer location in the port A;
• determining validity of a third mailbox bit associated with the next buffer location in the port A;
• if the third mailbox bit associated with the next buffer location in the port A is valid, then
• reading the next buffer location on the port A,
• forwarding the next buffer location on the port A to the output controller;
• and
• if the third mailbox bit associated with the next buffer location in the port A is not valid, then
• determining whether a fourth mailbox bit for the port B is valid, the fourth mailbox bit corresponding to the third mailbox bit for port A,
• if the fourth mailbox bit for the port B is valid, then
• reading a third buffer in the port B that corresponds to the fourth mailbox bit for the port B, and
• forwarding the third buffer from the port B to the output controller.

A method for communicating using a primary link and a redundant link, wherein data packets transmitted via the primary link and the redundant link are substantially the same, the method comprising:

• transmitting a first series of packets from a first transceiver to a second transceiver along a primary link;
• forwarding a second series of packets which corresponds to the first series of packets from the first transceiver to a third transceiver via a first cross-connect;
• transmitting the second series of packets from the third transceiver to a fourth transceiver via the redundant link;
• forwarding the second series of packets from the fourth transceiver to the second transceiver via a second cross-connect;
• storing a portion of the first series of packets at the second transceiver until a corresponding packet from the second series of packets is received by the second transceiver;
• determining a quality for the first series of packets and the second series of packets;
• and
• forwarding either the first series of packets or the second series of packets based on the quality;
• wherein the redundant link is a microwave link.