FORM 2
The Patent Act 1970
(39 of 1970)
&
The Patent Rules, 2005

COMPLETE SPECIFICATION
(SEE SECTION 10 AND RULE 13)

TITLE OF THE INVENTION
“Pairing MSS return link with BSS forward link to enable two way satellite communications”

APPLICANTS:

Name Nationality Address
Devas Multimedia Private Limited
Indian Regd Office: 102, Eden Park, 20, Vittal Mallya Road Bangalore 560 001

The following specification particularly describes and ascertains the nature of this invention and the manner in which it is to be performed:-

FIELD OF INVENTION
[001] This invention relates to satellite communication, and more particularly to pairing links employed in satellite communications.

BACKGROUND OF INVENTION
[002] Present day communication systems employ satellites for uplink and downlink transmission and reception of the data. Geostationary satellites provide a wide variety of services, some of which may be categorized into Fixed Satellite Service (FSS), Broadcast Satellite Service (BSS) and Mobile Satellite Services (MSS). Further, some of the data services that can be provided over the satellite include internet services, Virtual Private Network (VPN) services. In case of BSS systems, multimedia content is aggregated in the head end and transmitted to the satellite. Further, the multimedia content from the satellite are distributed on the forward link to multiple receivers that are located in the satellite footprint. Such systems distribute data across multiple receivers over the same forward link. Many a times such systems may face problems of frequency interferences and channel interference. Further, there is no means to ensure efficient utilization of the link and thus minimize the cost of employing the communications systems.
[003] In case of MSS Service, the system employs a pair of forward and return links so as to enable two way data communications to the users. The MSS system is basically one is to one i.e., it employs a link to send data to the user end and another link to receive data from the user end. Thus, multiple links are required to be provided for two way data transmission. There is no means to either eliminate any of the links, or to minimize the number of links used so as to minimize the cost of satellite transmission. In addition, there is no means to ensure that the efficiency of data transmission is adequate. Further, FSS systems serve data to ground terminals that do not change their locations. Therefore, there exist inefficiencies in usage of links in the aforementioned systems, and there is potential for increasing efficiency and for bringing down the cost of communication. Also, none of the present day systems provide means to achieve two way services as in MSS by employing the BSS link alone or in any combination of the same. Provisioning the BSS link as a component of two way services has not yet been explored. The conventional systems have been still employing BSS and MSS links separately in satellite communications. As a result the problem of high cost and reduced efficiency still persists in case of the satellite communication systems.

OBJECT OF INVENTION
[004] The principal object of this invention is to pair the return link of the MSS with the forward link of the BSS so as to achieve two way services.
[005] Another object of the invention is to eliminate the use of the forward link on the MSS by employing the paired link.

STATEMENT OF INVENTION
[006] Accordingly the invention provides a system and method for pairing a BSS forward link with a MSS return link for enabling two way satellite communications in satellite networks.
[007] The system is provided with means adapted for segmenting a forward link on the BSS into at least two components. Further allocating a first component for carrying broadcast content, allocating a second component for downlink data and pairing the second component of the BSS link with an uplink data component from a MSS return link.
[008] There is also provided a method for enabling two way communications in a satellite communication network. The method performs segmenting a BSS forward link into at least two components, allocates a first component for carrying broadcast content, allocates a second component for downlink data and pairs the second component of the BSS link with an uplink data component from a MSS return link.
[009] Also disclosed herein is a satellite for enabling two way communications in a satellite communication networks. The satellite is adapted for sending broadcast content on a first component of a BSS forward link, sending downlink data content on a second component of said BSS forward link and receiving data on a MSS return link.
[0010] Also disclosed herein is a user device for enabling two way communications in satellite communication networks. The device is adapted for receiving broadcast content on a first component of a BSS forward link, receiving downlink data content on a second component of the BSS forward link and sending data on a MSS return link.
[0011] Also disclosed herein is a MSS hub for enabling two way communications in a satellite communication network. The MSS hub is adapted for receiving data on a MSS return link from a satellite and sending the data on a terrestrial link to a BSS hub.
[0012] Also disclosed herein is a BSS hub for enabling two way communications in a satellite communication network. The BSS hub is adapted for receiving data content from a MSS hub on a terrestrial link, and sending the received data content as well as the broadcast content to a satellite on a multimedia satellite feeder uplink,
[0013] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF FIGURES
[0014] This invention is illustrated in the accompanying drawings, through out in which the reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0015] FIG. 1 illustrates the band distribution, according to embodiments as disclosed herein;
[0016] FIG. 2 depicts two way communication between a user device and a public network, according to embodiments as disclosed herein;
[0017] FIG. 3 depicts two way communication between two user devices, according to embodiments as disclosed herein;
[0018] FIG. 4 depicts the user device, according to embodiments as disclosed herein;
[0019] FIG. 5 depicts the BSS hub, according to embodiments as disclosed herein; and
[0020] FIG. 6 depicts the MSS hub, according to embodiments as disclosed herein.

DETAILED DESCRIPTION OF INVENTION
[0021] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0022] The embodiments herein achieve two way satellite communications for fixed and mobile users by pairing the MSS return link with the BSS forward link. Referring now to the drawings, and more particularly to FIGS. 1 through 6, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.
[0023] A method for enabling two way communications for fixed and mobile users is disclosed. The method is employed for two way satellite communications systems that employ geo stationary satellites. The method employs a mechanism wherein the links are paired so as to attain dual functionality with a single link. The method pairs the return link on the MSS with the forward link on the BSS and thus eliminating the need for the forward link on the MSS. It will no longer be using the MSS forward link to achieve two way communications. As a result of this, the functionality of the MSS forward link is carried out by the forward link on the BSS itself. Further, the bandwidth available on the BSS forward link is segmented into two parts, one part to carry broadcast content like audio/video and the other part to carry downlink data traffic from the satellite. The downlink data part is then paired with an uplink data from the user terminal using the MSS return link transponder on the satellite to derive two way data communications for the user terminal. The method thus minimizes the overall cost of the communication as the links employed for communication is reduced. In addition, the efficiency of communication is also improved as two way communications is achieved, coexisting with the content broadcast service.
[0024] FIG. 1 illustrates the band distribution, according to embodiments as disclosed herein. The figure depicts the frequency distribution on different links during two way satellite communication. The links employed are the BSS forward link and the MSS return link in order to enable two way communications. The bandwidth available on the BSS forward link is segmented into two i.e., one that carries the broadcast contents such as audio/video content and the second that carries downlink data content. The broadcast content is termed as IP1 and the downlink data content that carries data on the downlink is termed as IP2. Further, the downlink data component i.e., IP2 is paired with an uplink data termed as IP3 from the user terminal using the MSS return link on the satellite to enable two way communications for the user terminal. The exemplified audio/video content IP1 and data downlink IP2 are separated with an appropriate band gap as depicted in the figure. The band gap between the frequencies allocated for IP1 and IP2 takes care that the two carriers do not mutually interfere.
[0025] The feeder link IP1 may include but not be limited to audio/video contents and the feeder link IP2 may include but not be limited to the data contents received from the MSS hub via a terrestrial link. The audio/video contents and the data contents share the same BSS transponder on the satellite, but are separated in the allocation of frequencies. In fact there will be a small band gap between the frequencies allocated for IP1 and IP2 carriers so that they will not mutually interfere.
[0026] FIG. 2 depicts two way communications between a user device and a public network, according to embodiments as disclosed herein. The user device 201a employs two links: return link 208 for data transmission to the public networks 205 via the satellite 202 and the forward link 209 to receive data from the public networks 205 through a satellite 202. The user device 201a may be located anywhere in a service region of interest where the satellite 202 provides service.
[0027] The satellite 202 provides BSS payload for the forward link to any user device and a MSS payload for the return link from any user device. The BSS payload acts as a relay for the contents transmitted from the BSS hub 204 to the user device 201a via the uplink 210 to the satellite 202 and the downlink 209 from the satellite 202. The MSS payload acts as a relay for the contents transmitted from the user device 201a to the MSS hub 203 via the uplink 208 to the satellite 202 and downlink 206 from the satellite 202.
[0028] The satellite 202 is a geo stationary satellite. The geo stationary satellite 202 may be located over the equator at such a height that its period of revolution matches with the period of earth’s rotation over its axis. Also the longitude over which the geo stationary satellite 202 is maintained is such that the geo stationary satellite is radio visible over the service region of interest. The space segment considered includes one or more co-located and non-co-located geo stationary satellites 202. The geo stationary satellite 202 supports a plurality of services involving subsystems for broadcasting contents to the user device 201a and other subsystems for delivering data from the user device 201a.
[0029] In order to transmit the data from the user device 201a to the public networks 205, the user device 201a employs the return link. The data that is sent by the user device 201a is received by the satellite 202. In the satellite 202, the data is handled by the return link receive (MSS). The data is then sent to the return link transmit (MSS) as the data is to be transmitted to the MSS hub 203. The satellite 202 sends the data on the return link transmit (MSS) to the MSS hub 203 via the link 206. The MSS hub on receiving the data identifies that the data is meant to be sent to the public networks 205 and transmits the data to the public networks 205.
[0030] Further, data may be sent from the public networks 205 to the user device 201a. The public network 205 sends the data to the MSS hub 203. The MSS hub 203 then sends the data via the terrestrial link 207 to the BSS hub 204 as the data is meant for the user device 201a. In the BSS hub 204, the uplink content may include a combination of audio/video content and the data content received from MSS hub 203 via the terrestrial link 207. The BSS hub 204 then sends the data to the satellite 202 through the link 210. The satellite 202 receives the data on the forward link receive (BSS). The data is then handled by the forward link transmit (BSS), that sends the data to the user device 201a on the link 209. On the user device 201a, the data is received on the BSS forward link.
[0031] FIG. 3 depicts two way communications between two user devices, according to embodiments as disclosed herein. Two user devices 201a, 201b communicate with each other bidirectionally. The user devices 201a, 201b employ two links: return link for data transmission to the other user devices via the satellite 202 and the forward link to receive data from other user devices through the satellite 202. The communications happen through the satellite 202. The satellite 202 has the return link transmit (MSS), forward link receive (BSS), return link receive (MSS) and forward link transmit (BSS) for communicating data to and from the satellite 202 and the MSS hub 203 and BSS hub 204.
[0032] The user device 201a sends data to the user device 201b through the satellite 202. The data is sent on the user device 201a’s return link 208 that is meant to transmit the data to the satellite 202. On the satellite 202, the data is received on the return link receive (MSS). Further, the data is sent to the MSS hub 203 on the return link transmit (MSS) of the satellite 202 through the link 206. The MSS hub 203 then sends the data to the BSS hub 204 on the link 207. In an embodiment, the uplink may include this data received from MSS hub 203 via the terrestrial link 207, along with any broadcast audio/video content. The BSS hub 204 then sends the uplink to the satellite 202 on its forward link receive (BSS) 210. The data is then sent to the user device 201b on the forward link transmit (BSS) of the satellite 202. At the user device 201b, the data is received on the BSS forward link 302.
[0033] On similar lines, the user device 201b may send data to the user device 201a. The user device 201b sends the data on its return link 301 to the satellite 202. The return link receive (MSS) on the satellite 202 receives the data and sends the data to the MSS hub 203 on the return link transmit (MSS) 304 of the satellite 202. The MSS hub 203 sends the data to the BSS hub 204 through the link 305. The BSS hub 204 sends the data to the satellite 202 on the link 303. The forward link receive on the satellite 202 receives the data from the BSS hub 204 and sends the data to the user device 201a over the forward link transmit (BSS) 209. At the user device 201a, the data sent by the satellite is received on the BSS forward link.
[0034] FIG. 4 depicts the user device, according to embodiments as disclosed herein. The user device 201a, 201b communicates with the satellite 202 and other user devices for transmission and reception of the data. The user devices 201a, 201b may comprise of but are not limited to antennas 401, amplifier 402, frequency converter 403, and diplexer 404, filters 405, tuners 406, signal processor 407 and decoder 408.
[0035] The antennas 401 are employed for receiving the satellite transmissions and also to send data from the user device 201a, 201b to the satellite 202. The amplifiers 402 are employed for amplification of the signal received at the user device 201a, 201b. On the reception path, there is a low noise amplifier in order to eliminate any noise in the signal and to strengthen the signal. In the transmit path, there is a power amplifier employed to enhance the strength of the signal. During the transmission of data from the satellite 202 to the user device 201a, 201b, there may be a reduction in the strength of the signal and hence it may be necessary to amplify the strength of the signal at the user device 201a, 201b, which is done by the amplifier 402. The frequency converter 403 comprises of up converters and down converters. The up converter on the transmit path and the down converter on the receive path translate the satellite frequencies i.e., the S-band frequencies to an intermediate frequency suitable for processing by the user device 201a, 201b.
[0036] The diplexer 404 helps in isolation of transmit and receive paths. Since the user device 201a, 201b is involved in two way transmission, it is necessary to isolate the transmit path from the receive path so that there is no interference among the signals. The diplexer 404 serves the functions of isolating transmit and receive paths for the user device 201a, 201b. Filters 405 are employed for filtering the data content. Tuners 406 fine tune the signal to suit the requirements of the user device 201a, 201b. Signal processors 407 are employed for processing the signals received at the user device 201a, 201b. At the baseband processing level, the receive signal is demodulated, decoded, error corrections applied and the raw data is accessed. In the transmit path the raw data is appended with Forward Error Correction, coded and modulated. The decoders 408 are employed at the time of processing the signal, the signal received is decoded at the decoder 408.
[0037] FIG. 5 depicts the BSS hub, according to embodiments as disclosed herein. The BSS hub 204 provides multimedia satellite feeder uplink 210 for communication with the satellite 202. The BSS hub comprises of baseband system 501, up converter 502, RF amplifiers 503, antennas 504 and an A/V and data handling module 505.
[0038] The baseband system 501 may further comprise means for performing signal processing activities such as modulation, multiplexing, and so on. Up converter 502 translates the frequencies received from the terrestrial links into frequency (i.e. S band frequencies) suitable for transmission to the satellite 202. The RF amplifiers 503 are employed for amplification of the signal received at the BSS hub 204. The RF amplifiers 503 enhance the signal strength to provide sufficient signal for satellite reception. The antennas 504 are employed for reception of data received from the satellite 202 and for transmitting any data to the satellite 202. The A/V and data handling module 505 is meant for handling audio/video content and data content separately. The A/V and data handling module 505 receives audio/video content from external sources and the data content from the MSS hub 203. The external sources may include public networks 205 and the like. The data content from the MSS hub 203 is sent via the terrestrial link 207.
[0039] FIG. 6 depicts the MSS hub, according to embodiments as disclosed herein. The MSS hub 203 acts as a gateway for the data traffic in both the directions. The MSS hub 203 receives the return link from the satellite and appropriately interfaces it to the outside systems like the public networks 205. For data that is to be sent to the user devices 201a, 201b on the forward link, the MSS hub 203 may receive the data from the public networks 205 and deliver the data to the BSS hub 204. The data is delivered to the BSS hub 204 on the terrestrial link 207 for inclusion in the BSS feeder link 210 to the satellite 202. The MSS hub 203 receives the signal from the MSS Return Link transmitted by the satellite, identifies the destination of the packets and routes them accordingly (PSTN, Internet, cellular telephone networks, another user device etc). The MSS hub 203 also receives signals meant for transmission to the user device (from PSTN, Internet, cellular telephone networks, another user device etc) and transmits them to the BSS hub 204 for further transmission to the satellite 202 on the BSS link.
[0040] The MSS hub 204 may comprise of but is not limited to data content transmitter 601, RF amplifier 602, antenna 603, down converter 604 and an interface 605.
[0041] The data content transmitter 601 is adapted for handling data content that is to be sent to the satellite 202 or the user device 201a, 201b. The RF amplifiers 602 are employed for amplification of the signal received at the MSS hub 203. The RF amplifiers 602 eliminate low noise in the signal and enhance the signal strength. The antennas 603 are employed for reception of data received from the satellite 202. . The down converter 604 translates the frequencies received from the satellite 202 to frequencies suitable for public networks 205. The interface 605 provides a means for the external systems and devices to interact with the MSS hub 203.
[0042] In an embodiment, the user device 201a has two parts, namely the forward path (i.e. to the user device) and the Return path (i.e. from the user device). . By employing the BSS forward link in lieu of the MSS forward link two-way data services can as well be supported. As a result the need for the MSS forward link is eliminated as the paired BSS link serves the required functionality for the user devices.
[0043] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

WE CLAIM:-

1. A system for enabling two way communication in a satellite communication network, said system provided with at least one means adapted for
segmenting a BSS forward link into at least two components;
allocating a first component for carrying broadcast content;
allocating a second component for downlink data; and
pairing said second component of said BSS link with an uplink data component from a MSS return link.

2. The system as claimed in claim 1, wherein said system is adapted for segmenting said BSS forward link by allocating frequencies separately for said first component and said second component.

3. The system as claimed in claim 1, wherein said system is further provided with a MSS hub that is adapted for receiving said MSS return link from said satellite and interfacing said link to external systems.

4. The system as claimed in claim 1, wherein said system is further provided with a BSS hub that is adapted for receiving said broadcast content from external sources and said data content from the said MSS hub via a terrestrial link.

5. The system as claimed in claim 1, wherein said first component carries said broadcast content where said broadcast content is audio, video, and a combination of the same.

6. A method for enabling two way communication in a satellite communication network, said method comprising
segmenting a BSS forward link into at least two components;
allocating a first component for carrying broadcast content;
allocating a second component for downlink data; and
pairing said second component of said BSS link with an uplink data component from a MSS return link.

7. The method as claimed in claim 6, wherein said BSS forward link is segmented by allocating frequencies separately for said first component and said second component.

8. The method as claimed in claim 6, wherein said first component is received from public networks.

9. The method as claimed in claim 6, wherein said second component is received from a MSS hub.

10. The method as claimed in claim 6, wherein said method further comprises said MSS hub for receiving said MSS return link from said satellite and interfacing said link to external systems.

11. The method as claimed in claim 6, wherein said method further comprises said BSS hub for receiving said broadcast content from external sources and said data content from said MSS hub via a terrestrial link.

12. The method as claimed in claim 6, said first component carries said broadcast content where said broadcast content is audio, video and a combination of the same.

13. A satellite for enabling two way communication in a satellite communication networks, said satellite adapted for
sending broadcast content on a first component of a BSS forward link;
sending downlink data content on a second component of said BSS forward link; and
receiving data on a MSS return link.

14. The satellite as claimed in claim 13, wherein said satellite is adapted for receiving data on said MSS return link where said MSS return link is paired with said BSS forward link.

15. The satellite as claimed in claim 13, wherein said satellite is adapted for sending said broadcast content on said first component where said broadcast content is one of audio, video and a combination of the same.

16. The satellite as claimed in claim 13, wherein said satellite is further adapted for differentiating said first component and second component based on the frequencies allocated for said first and said second component.

17. The satellite as claimed in claim 13, wherein said satellite is a geo stationary satellite.

18. The satellite as claimed in claim 13, wherein said satellite is further adapted for receiving said data where said data is obtained from at least one of public networks, user device.

19. A user device for enabling two way communication in satellite communication networks, said device adapted for
receiving broadcast content on a first component of a BSS forward link;
receiving downlink data content on a second component of said BSS forward link; and
sending data on a MSS return link.

20. The user device as claimed in claim 19, wherein said first component and said second component are allocated frequencies separately.

21. The user device as claimed in claim 19, wherein said device is further adapted for receiving data on said BSS forward link where said BSS forward link is paired with said MSS return link.

22. A MSS hub for enabling two way communication in a satellite communication network, said MSS hub adapted for
receiving data on a MSS return link from a satellite; and
sending said data on a terrestrial link to a BSS hub.

23. The MSS hub as claimed in claim 22, wherein said MSS hub is adapted for receiving data where said data is obtained from at least one of user device, public networks.

24. The MSS hub as claimed in claim 22, wherein said MSS hub is adapted for sending said data where said data is obtained from at least one of user device, public networks.

25. A BSS hub for enabling two way communication in a satellite communication network, said BSS hub adapted for
receiving data content from a MSS hub on a terrestrial link; and
sending said received data content as well as broadcast content to a satellite on a multimedia satellite feeder uplink.

26. The BSS hub as claimed in claim 25, wherein said BSS hub is adapted for sending said broadcast content where said broadcast content is one of audio, video and a combination of the same.

27. The BSS hub as claimed in claim 25, wherein said BSS hub is adapted for receiving said data content from at least one of public networks, said MSS hub.

DATED 20TH SEP 2010

Mr. Nishant Kawalramani
Patent Agent