Bandwidth optimization and hitless transport in dynamic free space optical communications networks

• US 10,122,458 B2
• Filed: 08/30/2017
• Issued: 11/06/2018
• Est. Priority Date: 03/21/2014
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Sackman, Ronald Ward, Sullivan, Scott Charles, Meier, John
• Primary Examiner(s): Woldekidan, Hibret
• Application Number:
  US15/690,656
• Publication Number:
  US 20170366265A1
• Time in Patent Office: 433 Days
• Field of Search: 398125, 398121, 398124, 398118, 398 79, 398 83, 398 2, 398 5, 398 45, 398 50
• CPC Class Codes: H04B 10/118 specially adapted for satellite communication
• CPC Class Codes: H04J 14/022 For interconnection of WDM optical networks
• CPC Class Codes: H04J 14/0271 Impairment aware routing
• CPC Class Codes: H04J 14/0282 WDM tree architectures

Abstract

A system for optical communications may include a multiplicity of optical communications relay platforms that each move above a surface of the earth. Each relay platform may include a relay link for communications between adjacent relay platforms. The system may also include a plurality of ground stations. Each ground station may be configured to communicate with another of the ground stations through at least one of the relay platforms. Each ground station may include an optical communications link for optical communications with successive relay platforms. The optical link of each ground station may be configured for handover connections between the successive relay platforms as the relay platforms move relative to the earth. The system may additionally include a network operations center having a link controller. The link controller may be configured to control switching of the communications links for hitless transmission between the ground stations.

Claims

1. A system for optical communications, comprising:

a multiplicity of optical communications relay platforms that each move relative to earth and above a surface of the earth, each optical communications relay platform comprising a relay link for communications between adjacent optical communications relay platforms;

a plurality of ground stations at different locations on the surface of the earth, each ground station comprising one or more optical communications links for optical communications with successive optical communications relay platforms, the optical communications links of each ground station being configured for handover connections between the successive optical communications relay platforms as the optical communications relay platforms move relative to the earth, wherein each ground station further comprises an optical switch for sending and receiving optical signals from the optical communications link; and

a link controller, the link controller being configured to control switching of the optical communications links and the relay links for hitless transmission of optical communications signals, the link controller controlling at least one of switching between the optical communications links or switching between the relay links in response to at least one of degradation of an optical communications link or movement of the optical communications relay platforms relative to the earth.

2. The system of claim 1, wherein degradation is determined by polling parameters to detect that at least one performance indicator of a plurality of performance indicators has exceeded a preset threshold, the plurality of performance indicators comprising bit error rate, packet loss, jitter, signal strength, and latency.

3. The system of claim 1, wherein the handover connections from the plurality of ground stations between successive optical communications relay platforms comprises a make before break connection.

4. The system of claim 1, wherein each of the multiplicity of optical communications relay platforms comprises a laser communications relay platform.

5. The system of claim 1, wherein each of the multiplicity of optical communications relay platforms comprises one of a low earth orbit satellite, a medium earth orbit satellite and an unmanned aerial vehicle.

6. The system of claim 1, wherein the plurality of ground stations are configured in at least one optical ring, wherein ground stations within a particular optical ring communicate with each other via the optical ring.

7. The system of claim 1, further comprising a variable speed lambda network comprising a plurality of variable speed wavelength division multiplexing (WDM) lambdas, wherein the link controller is further configured to control functions comprising:

admission of a variable speed WDM lambda to the variable speed lambda network, each variable speed WDM lambda having a tunable speed;

modification of a speed of a particular variable speed WDM lambda; and

optimization of bandwidth of the variable speed WDM lambdas.

8. The system of claim 7, wherein the variable speed lambda network further comprises:

a provider optical add-drop multiplexer (ADM);

a customer optical ADM, wherein the plurality of variable speed WDM lambdas provide communications between the provider optical ADM and the customer optical ADM; and

a customer optical ring coupled to the customer optical ADM.

9. The system of claim 7, wherein the link controller comprises an algorithm configured to perform a method comprising:

receiving a new request from a customer, the new request comprising one of a request for a new variable speed WDM lambda or a speed change request for an existing variable speed WDM lambda;

retrieving an active topology map of the variable speed lambda network from a database;

executing a multi-commodity network flow optimization based on the active topology map of the variable speed lambda network;

configuring network elements to support the new request in response to the new request being admitted based on the multi-commodity network flow optimization, the network elements comprising a provider optical ADM and the plurality of variable speed WDM lambdas;

updating bandwidth parameters of a link of a network topology graph associated with the customer; and

notifying the customer that the new request has been granted and provisioned.

10. The system of claim 1, wherein the optical communications link comprises a laser communications link and each ground station further comprises:

a router for sending and receiving the optical signals from the optical switch; and

a sensor for detecting an environmental change, wherein the optical communications link is handed over to another optical communications link or a next optical communications relay platform in response to the environmental change degrading communications between the ground station and a current optical communications relay platform below a predetermined link quality threshold.

11. The system of claim 1, further comprising a network operations center, the network operations center comprising:

a network performance manager polling at least the plurality of ground stations for a change in quality of the optical communications link, and to poll at least one external sensor associated with each ground station for an environmental change, and the network performance manager further generating a threshold notification in response to at least one of the change in quality of the optical communications link exceeding a link quality threshold or the environmental change exceeding an environmental threshold;

a database configured to receive an environmental change notification from the at least one external sensor in response to the environmental change, and to receive a link quality change notification from a particular ground station in response to the change in link quality of the optical communications link associated with the particular ground station, and to receive a notification in response to the network performance manager generating the threshold notification; and

a correlation engine associated with the database, the correlation engine transmitting a signal to the link controller to initiate a link decision process for switching at least one of the optical communications links or the relay links in response to a correlation policy match based on at least one of the change in quality of the optical communications link, the environmental change or the threshold notification.

12. A method for dynamically changing free space optical communications links for hitless transmission, the method comprising:

detecting degradation of an optical communications link, the optical communications link being from a ground station to an optical communications relay platform;

determining a correlation policy match based on the degradation of the optical communications link, wherein the correlation policy match indicates that a switch or change of at least one of;

the optical communications link to another optical communications link, the around station to another ground station, or the optical communications relay platform to another optical communications relay platform is warranted;

transmitting a signal to initiate a link decision process for switching the at least one of the optical communications link, the ground station or the optical communications relay platform in response to the correlation policy being matched;

identifying a particular optical communications link for optical communications between the ground station and the optical communications relay platform based on at least environmental conditions and communications traffic load offered by the particular optical communications link;

determining a new cross-link between the optical communications relay platform and a successive optical communications relay platform based on the link decision process; and

switching at least one of the optical communications link to the other optical communications link or a relay link between the optical communications relay platform and the successive optical communications relay platform in response to at least one of the degradation of the optical communications link or movement of the optical communications relay platform.

13. The method of claim 12, wherein detecting the degradation of the optical communications link comprises polling at least the ground station for a change in quality of the optical communications link.

14. The method of claim 12, further comprising detecting an environmental change that causes degradation of the optical communications link, wherein detecting the environmental change comprises polling at least one external sensor associated with the ground station for the environmental change.

15. The method of claim 12, wherein the link decision process comprises:

determining an optimal ground station for optical communications with the optical communications relay platform based on at least environmental conditions, terrestrial transport cost, traffic flow optimization or maintenance schedules; and

determining an optimal optical communications link between the optimal ground station and the optical communications relay platform based on environmental conditions and link performance parameters.

16. A method for dynamically changing free space optical communications links for hitless transmission, the method comprising:

determining an optimal ground station for optical communications with a particular optical communications relay platform in response to detecting degradation of an optical communications link;

switching to the optimal ground station in response to the optimal ground station being different from a current ground station;

determining an optimal optical communications link between the optimal ground station and the particular optical communications relay platform;

switching to the optimal optical communications link in response to the optimal optical communications link being different from a current optical communications link;

determining an optical cross-connect change between the particular optical communications relay platform and a successive optical communications relay platform in response to at least one of switching to the optimal ground station or switching to the optimal optical communications link; and

switching to a new optical cross-connect based on at least one of an optical communications relay platform configuration, available bandwidth or ground station availability.

17. The method of claim 16, further comprising identifying a particular lasercom head for optical communications between the optimal ground station and the particular optical communications relay platform based on at least one of environmental conditions or communications traffic load offered by the particular lasercom head.

18. The method of claim 16, further comprising updating a constellation topology in response to a new ground station, a new optical communications link or a new optical cross-connect.

19. The method of claim 16, wherein detecting degradation of the optical communications link comprises polling the current ground station for a change in quality of the optical communications link.

20. The method of claim 16, further comprising detecting an environmental change that causes degradation of the optical communications link, wherein detecting the environmental change comprises polling at least one external sensor associated with the current ground station for the environmental change.