EP3637639A1

EP3637639A1 - Satellite broadcast signal receiver, method of operation of satellite broadcast signal receivers and switch therefor

Info

Publication number: EP3637639A1
Application number: EP18199406.2A
Authority: EP
Inventors: Ísmail YILMAZLAR
Original assignee: Vestel Elektronik Sanayi ve Ticaret AS
Current assignee: Vestel Elektronik Sanayi ve Ticaret AS
Priority date: 2018-10-09
Filing date: 2018-10-09
Publication date: 2020-04-15

Abstract

A plurality of satellite broadcast signal receivers (10) are connected in series to a low-noise block downconverter, LNB (22), of a satellite dish and operate according to single cable distribution. One of the receivers (10) transmits a control signal ultimately to be received by the LNB (22) to select a channel to be received from the LNB (22) for the receiver (10). If the one receiver (10) is the first receiver (10₁) in the series connection of receivers to the LNB (22), the one receiver (10₁) transmits the control signal to the LNB 2. Otherwise, if the one receiver (10) is further down the series connection of receivers (10) to the LNB (22), the one receiver (10_x) transmits the control signal to another receiver (10_x-1) that is further up the series connection of receivers (10) to the LNB (22) for that other receiver to pass on the control signal for the control signal to be received ultimately by the LNB (22).

Description

Technical Field

The present disclosure relates to a method of operating a plurality of satellite broadcast signal receivers, to a satellite broadcast signal receiver and to a switch for use in a single cable distribution system.

Background

A satellite broadcast signal receiver is connected in use to a LNB (low-noise block downconverter) of a satellite dish in order to receive signals broadcast by a satellite, typically for receiving television and/or radio channels. The receiver sends control signals to the LNB as required in order to reconfigure the LNB to select a desired channel that can be received by the satellite dish.
So-called "single cable distribution" (sometimes known by the name "Unicable") is known which enables the simultaneous delivery of channels from a single satellite dish to multiple receivers (typically for multiple users) over a single coaxial cable. In known single cable distribution, each receiver is allocated a "user band" having a different centre frequency (an "intermediate frequency") for the signals that carry the channel signal (i.e. the broadcast programme) and that are passed from the satellite dish to the receiver. However, a problem arises in practice in that if two (or more) receivers are attempting to send control signals to the LNB at the same time, the control signals or messages can collide and therefore be lost or corrupted.

Summary

According to a first aspect disclosed herein, there is provided a method of operating a plurality of satellite broadcast signal receivers which are connected in series to a low-noise block downconverter, LNB, of a satellite dish and which are operating according to single cable distribution, wherein a first of the receivers is closest in the series connection of receivers to the LNB and others of the receivers are further down the series connection of receivers to the LNB, the method comprising:

one of the satellite broadcast signal receivers transmitting a control signal ultimately to be received by the LNB to select a channel to be received from the LNB for said receiver;
wherein:
1. (a) if said one receiver is the first receiver in the series connection of receivers to the LNB, said one receiver transmits the control signal to the LNB,
2. (b) else if said one receiver is further down the series connection of receivers to the LNB, said one receiver transmits the control signal to another receiver that is further up the series connection of receivers to the LNB for said other receiver to pass on the control signal for the control signal to be received ultimately by the LNB.

This avoids collisions between control signals transmitted by plural satellite broadcast signal receivers occurring. A second communication channel is provided between the satellite broadcast signal receivers. In an example, each receiver sends its control signals up the series or chain of receivers using the second communication channel, with each receiver passing on the control signal received from other receivers until ultimately the control signal(s) is (are) received at the LNB.
In the case (a) where said one receiver is the first in the series of receivers, i.e. the receiver that is closest (logically) to the LNB, said one receiver transmits the control signal effectively directly to the LNB, i.e. the control signal is not sent via any other receivers in the series; the control signal may nevertheless be sent via a splitter or switch, etc.
In an example, in the case (b):

(c) if said other receiver is the first receiver in the series connection of receivers to the LNB, said other receiver transmits the control signal received from said one receiver to the LNB,
(d) else if said other receiver is further down the series connection of receivers to the LNB, said other receiver transmits the control signal received from said one receiver to yet another receiver that is further up the series connection of receivers to the LNB for said yet another receiver to pass on the control signal received from said one receiver for the control signal to be received ultimately by the LNB.

In an example, said other receiver transmits the control signal received from said one receiver ultimately to be received by the LNB, and said other receiver transmits its own control signal ultimately to be received by the LNB to select a channel to be received from the LNB for said other receiver.
In an example:
at least some of the receivers are connected to respective switches, the switches being connected in series to each other, the switches receiving channel signals from the LNB and passing the channel signals to the receiver connected to the switch and/or down the series of connected switches to be passed to the receivers respectively connected to the switches in accordance with the channel(s) selected by the respective receivers.
In an example, the switches are arranged to receive control signals transmitted by the receiver connected to the switch;
wherein the switch that is connected to the first receiver in the series connection of receivers is connected to the LNB to pass control signals to the LNB and to receive channel signals from the LNB, each other switch being connected to the receiver that is further up the series of receivers and operating to pass control signals received at the switch to said receiver that is further up the series of receivers for said receiver.
That receiver that is further up the series of receivers can then pass on the control signal, either to the LNB if that receiver is the first in the series of receivers or to yet another receiver further up the series if not.
The connections between the switches and the receivers may be for example wired connections.
In an example, at least some of the receivers have a wireless connection to a receiver that is further up the series of receivers for wirelessly transmitting control signals up the series of receivers.
In the case that all of the receivers (other than the first receiver) have such wireless connections to a receiver that is further up the series of receivers, this avoids having to modify switches that are conventionally provided in single cable distribution system. This means that standard switches can be used in such an arrangement.
According to a second aspect disclosed herein, there is provided a switch for use in a single cable distribution system in which a plurality of satellite broadcast signal receivers are connected in series to a low-noise block downconverter, LNB, of a satellite dish to receive channel signals from the LNB, the switch comprising:

a first port for receiving channel signals;
a second port for connecting the switch to the first port of another switch to pass channel signals for other receivers received at the first port of the switch to said first port of said other switch;
a third port for connecting the switch to a satellite broadcast signal receiver to pass channel signals for said satellite broadcast signal receiver to said satellite broadcast signal receiver and to receive control signals from said satellite broadcast signal receiver; and
a fourth port for connecting the switch to another satellite broadcast signal receiver that is further up the series connection of receivers to pass control signals to said other satellite broadcast signal receiver;
the switch being constructed and arranged such that:
- channel signals received in use at the first port and intended for a receiver connected in use to the third port are passed to said receiver connected to the third port;
- channel signals received in use at the first port and intended for another receiver are passed to the second port to be passed to the first port of another switch;
- control signals received in use at the third port are passed to the fourth port to be passed in use to another satellite broadcast signal receiver that is further up the series connection of receivers if the fourth port is connected to another satellite broadcast signal receiver; and
- control signals received in use at the third port are passed to the first port to be passed in use to a said LNB if the fourth port is not connected to another satellite broadcast signal receiver.

According to a third aspect disclosed herein, there is provided a satellite broadcast signal receiver for use in a single cable distribution system, the receiver comprising:

a channel signal input through which channel signals can be received from a low-noise block downconverter, LNB, of a satellite dish;
a control signal output through which control signals for a said LNB can be passed to select a channel to be received from a said LNB for the receiver; and
a control signal input through which control signals for a said LNB from other satellite broadcast signal receiver can be received;
the receiver being constructed and arranged such that if the receiver is not the first receiver in the series connection of receivers to a said LNB, then the receiver transmits control signals through its control signal output to be received at a control signal input of another receiver in the series connection of receivers to a said LNB for said other receiver to pass said control signals on, the control signals including control signals to select a channel to be received from a said LNB for the receiver, and the control signals including control signals to select a channel to be received from a said LNB for other receivers further down the series connection of receivers and received a the receiver;
the receiver being constructed and arranged such that if the receiver is the first receiver in the series connection of receivers to a said LNB, then the receiver transmits control signals to the LNB, the control signals including control signals to select a channel to be received from a said LNB for the receiver, and the control signals including control signals to select a channel to be received from a said LNB for other receivers further down the series connection of receivers and received a the receiver.

In an example, the control signal input and the control signal output provide for wireless communications from the receiver to another receiver.
The control signals that are passed up the series of receivers in a single cable distribution system in practice can be passed wirelessly up the series of receivers. Ultimately, the first receiver that is closest (logically) to the LNB transmits its own control signal the to LNB, along with any other control signals received from other receivers further down the series, typically over a wired connection to the LNB.
There may also be provided a method of operating a plurality of satellite broadcast signal receivers which are connected in series to a low-noise block downconverter, LNB, of a satellite dish and which are operating according to single cable distribution, wherein a first of the receivers is closest in the series connection of receivers to the LNB and others of the receivers are further down the series connection of receivers to the LNB, the method comprising:

each receiver, that is not the first receiver, when required to transmit a control signal which is ultimately to be received by the LNB to select a channel to be received from the LNB for said receiver, transmitting said control signal such that said control signal is received by the next receiver up the series connection of receivers;
each receiver, that is not the first receiver and that has received a control signal from a receiver further down the series of receivers, transmitting said received control signal such that said received control signal is received by the next receiver up the series connection of receivers; and
the first receiver transmitting control signals that are received from other receivers further down the series of receivers such that said control signals are received by the LNB, the first receiver also transmitting control signals that are to select a channel to be received from the LNB for the first receiver such that said control signals are received by the LNB.

Brief Description of the Drawings

To assist understanding of the present disclosure and to show how embodiments may be put into effect, reference is made by way of example to the accompanying drawings in which:

Figure 1 shows schematically a first example of plural satellite broadcast signal receivers connected to a satellite dish in a single cable distribution system; and
Figure 2 shows schematically a second example of plural satellite broadcast signal receivers connected to a satellite dish in a single cable distribution system.

Detailed Description

As mentioned, a satellite broadcast signal receiver is connected in use to a LNB of a satellite dish in order to receive signals broadcast by a satellite, typically for receiving television and/or radio channels. The receiver sends control signals to the LNB as required in order to reconfigure the LNB to select a desired channel that can be received by the satellite dish.
So-called "single cable distribution" (sometimes known by the name "Unicable") enables the simultaneous delivery of channels from a single satellite dish to multiple receivers (typically for multiple users) over a single cable from the LNB, which is typically a coaxial cable. In known installations, both bidirectional data/signals and power are sent over the single cable. In known single cable distribution, each receiver is allocated a "user band" having a different centre intermediate frequency for the signals that carry the channel signal (i.e. the broadcast programme) and that are passed from the satellite dish and LNB to the receiver. This enables multiple receivers to use the same satellite dish, which is useful when for example the multiple receivers are all located in the same building as a single satellite dish provided on the building can provide services for the multiple receivers. Moreover, a single cable can connect the satellite dish to all of the multiple receivers, which is convenient for users or installers of the system. (For completeness, it is mentioned that in a typical installation there is a single cable from the LNB into the dwelling or other building in which the satellite broadcast signal receivers are located, even if ultimately there may be separate cables from that single cable to the individual satellite broadcast signal receivers to provide the final connection to the receivers.)
However, as mentioned, a problem arises in practice in that if two (or more) receivers are attempting to send control signals to the LNB at the same time, the control signals or messages can collide and therefore be lost or corrupted. This can mean that the control signals or messages do not reach the LNB and/or cannot be decoded correctly by the LNB.
The CENELEC (European Committee for Electrotechnical Standardization) EN 50494 Standard entitled "SATELLITE SIGNAL DISTRIBUTION OVER A SINGLE COAXIAL CABLE IN SINGLE DWELLING INSTALLATIONS" suggests a number of arrangements for handling collisions of messages in such circumstances, but these are not practical or satisfactory. For example, if a receiver detects failure of a control message, it is suggested that the message is retransmitted by the receiver concerned, with a pseudorandom delay. However, this introduces long delays in control messages reaching the LNB, which can be disconcerting and confusing to the user who may think that the receiver or another part of the system is not operating or responding correctly.
To illustrate this further, Figure 1 shows schematically an example of plural satellite broadcast signal receivers 10 connected to a satellite dish 20. The satellite broadcast signal receivers 10 may be for example television sets, set-top boxes, PVRs (personal video recorders, also known as a DVRs or digital video recorders), expansion cards for computers, etc., which each may have one or more tuners, and which may in general be the same type of device or different devices. The satellite broadcast signal receivers 10 have one or more processors 11, non-volatile data storage 12 for storing data, etc. The satellite dish 20 equipment is sometimes referred to as an outdoor unit (ODU), whether actually located outdoors or not. The satellite broadcast signal receivers 10 are sometimes referred to as indoor units (IDUs) or integrated receiver/decoders (IRDs).
Each satellite broadcast signal receiver 10 is connected to the satellite dish 20 by a wired connection 30. The system shown is a single cable distribution system. Accordingly, there is a single wired connection 30 out of the satellite dish 20 to the different satellite broadcast signal receivers 10 (though there are also individual final wired connections 31 to the different satellite broadcast signal receivers 10 which are connected to the single cable 30 via splitters not shown in Figure 1). In the example shown, there are eight satellite broadcast signal receivers 10_1-n (some being indicated by the ellipsis ...), which is a typical maximum for single cable distribution systems. The wired connection 30 is typically a coaxial cable, though a plastics optical fibre or other connection may be used. The receivers 10_1-n are connected in series, with a first receiver 10₁ being (logically) closest to the LNB 22 and the other receivers 10_2-n being progressively (logically) further from the LNB 22.
As is well known per se, the satellite dish 20 has a parabolic reflector 21 which focusses signals received from a broadcasting satellite (not shown) to a so-called LNB (low-noise block downconverter) 22. The LNB 22 is located at the focal point of the parabolic reflector 21, or at least as close to the focal point as is practical. An LNB 22 is typically in effect a combination of a low-noise amplifier, frequency mixers, local oscillators and intermediate frequency (IF) amplifiers. In general, some of these components, including for example the mixers, may be provided as separate components or modules or may all be included in a single LNB block or module. The LNB may be implemented by or use one or more special semiconductor chips often referred to as "satellite channel routers".
The LNB 22 receives the (microwave) signal transmitted by the broadcasting satellite and collected by the parabolic reflector 21, amplifies it, and down converts the block of frequencies to a lower block of intermediate frequencies (IF). The down conversion at the LNB 22 permits the use of relatively inexpensive coaxial cable 30 to connect the LNB 22 to the satellite broadcast signal receivers 10. The cable 30 is connected to the LNB 22. The LNB 22 sends a combined signal, which includes channels signals at the different intermediate frequencies for the different receivers 10, down the cable 30. The combined signal is tapped or split to reach every receiver 10 as necessary.
As is known, the broadcast signals transmitted by the satellite for receipt by satellite dishes 20 are typically in one or more specific frequency bands and may use a specific polarisation. For example, in Europe, the frequencies currently used by digital video broadcast satellite services DVB-S/DVB-S2 are 10.7-12.75 GHz on two polarisations H (Horizontal) and V (Vertical). (In the US, left and right circular polarisation is used rather than horizontal and vertical polarisation as used in Europe and at least most other countries.) This range is divided into a "low band" with 10.7-11.7 GHz and a "high band" with 11.7-12.75 GHz. This results in two frequency bands, each with a bandwidth of about 1 GHz, each with two possible polarisations. In the LNB 22, these bands are down converted to a frequency in the range 950-2150 MHz, which is the frequency range allocated for the satellite service on the coaxial cable between LNB 22 and the receivers 10. Numerous individual channels (i.e. television and/or radio channels) are transmitted within each band and have one polarisation or the other.
As illustrated schematically in Figure 1, in known single cable distribution, each receiver 10_1-n is allocated a "user band" UB1, UB2,... having a different centre intermediate frequency for the signals that carry the channel signal (i.e. the broadcast programme) and that are passed from the LNB 22 of the satellite dish 20 to the receiver 10. The different intermediate frequencies can be allocated to the receivers 10 in a number of ways. For example, in accordance with the CENELEC (European Committee for Electrotechnical Standardization) EN 50494 Standard entitled "SATELLITE SIGNAL DISTRIBUTION OVER A SINGLE COAXIAL CABLE IN SINGLE DWELLING INSTALLATIONS", a receiver 10 transmits a command to the LNB 20 for the LNB 20 to generate a number of signals at the available intermediate frequencies, and the receiver 10 adopts the first frequency that it encounters when scanning across the band of signals. Alternatively or additionally, the LNB 22 can instruct the receivers 10 as to which intermediate frequency to use. The LNB 22 has plural local oscillators, each for generating a different one of the plural intermediate frequencies which are used for providing signals to the individual receivers 10 over the cable 30.
In order to be able to receive and demodulate a particular channel as selected by a user, the receiver 10 associated with the user transmits a control signal to the LNB 22 to cause the LNB 22 to receive and process the correct corresponding signal that is broadcast by the satellite. For example, the control signal may cause the LNB 22 to receive and process the corresponding band (high or low) having the corresponding polarisation (e.g. horizontal or vertical) that is broadcast by the satellite. As a specific example to illustrate this, the United Kingdom television channel BBC One HD is (currently) broadcast with a frequency of 10,847 GHz and vertical polarisation. Accordingly, to enable the user to watch BBC One HD, a control signal is sent by the receiver 10 to the LNB 22 to instruct the LNB 22 to tune to the low frequency band with vertical polarisation and to deliver the channel signals for that channel at the user band or intermediate frequency selected by or for that receiver.
A number of different arrangements and standards for such control signals are possible and are used. As a specific example to illustrate this, a voltage of 13V may be transmitted to select a vertical polarisation and a voltage of 18V may be transmitted to select a horizontal polarisation; and a "tone signal" of 22kHz may be transmitted to select the high frequency band, the absence of a tone signal being taken by the LNB 22 as selection of the low frequency band.
In operation in known single cable distribution systems and as mentioned, the control signals or messages from the receivers 10 to the LNB 22 are all sent independently over the single cable 30. This can cause those messages effectively to collide, meaning that they may not reach the LNB 22 at all or are corrupted before reaching the LNB 22.
To overcome this, in examples herein receivers 10 that are not the first receiver 10₁ that is (logically) closest to the LNB 22 send their control signals to the next receiver up the series for those other receivers in turn to pass on the control signals until, ultimately, the first receiver 10₁ passes the control signals to the LNB 22. That is, effectively a second communication channel is provided for control signals to be passed up the series of receivers 10. Each receiver 10 passes on control signals received from receivers 10 further down the series, as well as its own control signals. The receivers 10 operate to avoid collisions between control signals. In this way, no control signals are lost, which means that no control signals from a receiver 10 to retune to receive a different channel are lost and retuning can be carried out more quickly than in known single cable distribution systems. Some examples of how to provide the second communication channel are discussed below.
As a first example and as indicated schematically in Figure 1, a second communication channel 40 can be provided directly between the receivers 10. The second communication channel 40 can be used for one receiver 10_x to pass control signals up to the next receiver 10_x-1 in the series connection to the LNB 22. Each receiver 10 is arranged to pass its own control signal, for example to select a different channel to be sent by the LNB 22 to the receiver 10, up to the next receiver 10, as well as to pass up to the next receiver 10 any other control signals that have been received at the receiver 10 from other receivers 10 further down the series connection to the LNB 22. Finally, the first receiver 10₁ which is closest to the LNB 22 passes its own control signal and any control signals received from receivers 10 further down the series onto the cable 30 to pass directly to the LNB 22. In this way, the control signals from the receivers 10 to the LNB 22 are not randomly or pseudorandomly sent over the single shared cable 30, which avoids collisions between the control signals from the different receivers 10. Operation of the receivers 10 in this way may be achieved through suitable control by the operation of the processors 11 of the receivers 10.
The second communication channel 40 between the receivers 10 may be achieved by wired connections, using an appropriate protocol, such as for example UART (Universal Asynchronous Receiver-Transmitter), I2C (Inter-Integrated Circuit), SPI (Serial Peripheral Interface), RS232, etc. Alternatively or additionally, the second communication channel 40 between the receivers 10 may be achieved by wireless connections, using for example WiFi, Bluetooth, etc. The second communication channel 40 between some of the receivers 10 may be provided by wired connections and the second communication channel 40 between others of the receivers 10 may be provided by wireless connections. In general, wireless connections are likely to be more convenient for users, especially as the receivers 10 may be located in different rooms or even different dwellings (for example, houses or flats or apartments) belonging to different people.
Providing the second communication channel 40 in effect directly between the receivers 10 as just described requires modification of standard satellite broadcast signal receivers, but can avoid having to modify other components of a standard single cable distribution system.
Referring to Figure 2, another example of a single cable distribution system making use of aspects of the present disclosure is shown schematically. The same or corresponding devices and components as in Figure 1 have the same reference numerals and the detailed description of those devices and components will not be repeated here.
As such, in Figure 2, plural satellite broadcast signal receivers 10 are connected to an LNB 22 of a satellite dish. In Figure 2, the LNB 22 is represented by plural local oscillators 24 which respectively generate a different one of the plural intermediate frequencies which are used for providing signals to the individual receivers 10.
A wired connection 30 is provided from the LNB 22 to the receivers 10 for carrying channel signals from the LNB 22 to the receivers 10. Notably, in this example, the wired connection 30 only also carries control signals from the first receiver 10₁, which is closest to the LNB 22, to the LNB 22. Control signals from other receivers 10 to the LNB 22 pass over a second, different communication channel, as will be described further below.
Figure 2 also shows a plurality of splitters or switches 50, there being one switch 50 for each receiver 10. The plural switches 50 may be provided as separate units or may be provided together in a single switching box. Of course, there may not be the maximum number of permitted receivers 10 in an actual implementation, and therefore some switches may not be connected to a receiver 10 in some implementations. The switches 50 are all connected to the wired connection 30.
Switches or splitters or the like are used in conventional single cable distribution systems to allow the combined signal carrying channel signals from the LNB to be tapped or split to reach every receiver as necessary. For example, as mentioned, typically each receiver is allocated a "user band" having a different centre frequency (an "intermediate frequency") for the signals that carry the channel signal (i.e. the broadcast programme) and that are passed from the satellite dish to the receiver via the switches 50. However, the switches 50 in this example of the present disclosure are different from conventional switches as used in conventional single cable distribution systems, as will be discussed.
In particular, in this example each switch 50 has (at least) four ports 52, 54, 56, 58. Each switch 50 further has a processor 60 for controlling operation of the switch 50.
In each case, the first port 52 receives channel signals which ultimately are sent down the wired connection 30 by the LNB 22. The channel signals are each sent at the correct intermediate frequency for the respective intended receiver 10 as set by the different local oscillators 24. The second ports 54 of each switch 50 (other than the last switch 50_n) are connected to the first port 54 of the next switch 50 down the series of switches 50. Channel signals from the LNB 22 and received at a first port 52 of a switch 50 are therefore passed to the second port 54 of that switch 50, in turn to be sent out of the second port 54 to be received at the first port 52 of the next switch 50 down the series of switches 50. In the case of the first switch 50₁, which is closest to the LNB 22, this switch 50₁ receives it channel signals directly from the LNB 22 (i.e. not via any other switch 50). All other switches 50 receive their channel signals from the previous switch 50 up the series of switches 50. The last switch 50_n, which is furthest from the LNB 22, does not have any connection to its second port 54 as the last switch 50_n, does not need to send channel signals down the series of receivers 10 as there are no further receivers 10 beyond the last receiver 10_n.
The third ports 56 of the switches 50 are connected respectively to the receivers 10. The third port 56 of each switch 50 receives channel signals received at the first port 52 of the switch 50, and passes the channel signal intended for its connected receiver 10 to that receiver 10 by virtue of the receiver 10 being tuned to the intermediate frequency for that particular channel signal. Also, the third port 56 of the switches 50 receive control signals from its connected receiver 10. Such control signals may be or include control signals generated by the connected receiver 10, for example to cause the LNB 22 to tune to a different channel for that connected receiver 10. Such control signals may be or include control signals generated by another receiver 10 further down the series of receivers 10, and which are being relayed to the LNB 22 though the receivers 10 further up the series of receivers 10.
Finally, the fourth ports 58 of the switches are connected to the previous receiver 10 further up the series of receivers 10. The fourth ports 58 are used to pass control signals that are received at the third port 56 of the switch 50 to the previous receiver 10 further up the series of receivers 10. For completeness it is mentioned that the first switch 50₁, which is closest to the LNB 22, does not have any connection to its fourth port 58 as the first switch 50₁ sends control signals directly to the LNB 22.
The connection between a receiver 10 and the third port 56 of the switch 50 connected to that receiver 10 carries control signals up the series of receivers 10 and also carry a channel signal received from the LNB 22 and intended for that specific receiver 10. As such, the connection itself may be a simple wired connection, such as a coaxial cable.
On the other hand, the connection between the fourth port 58 of a switch 50 to the previous receiver 10 in the series of receivers 10 typically carries control signals from one or more receivers 10 that are further down the series of receivers 10. As such and depending on the protocol used for carrying these control signals, these connections may be simple wired connections, using for example coaxial cable, or may be wired connections that use an appropriate protocol, such as for example UART (Universal Asynchronous Receiver-Transmitter), I2C (Inter-Integrated Circuit), SPI (Serial Peripheral Interface), RS232, etc. In another example, these connections may be wireless connections, using for example WiFi or Bluetooth, etc.
In use and similarly to the direct connection example of Figure 1, if a user commands a receiver 10 to retune, the receiver 10 sends its corresponding control signals, which ultimately are intended to be received at the LNB 22, to the switch 50 connected to that receiver 10, in particular to the third port 56 of that switch 50. For all receivers 10 and switches 50 that are not the first in the series connection to the LNB 22 (i.e. not the receiver 10₁ and switch 50i in Figure 2), those control signals are passed by the switch 50 to the fourth port 58 of the switch 50 and from there sent to the next receiver 10 up the series of receivers 10.
That next receiver 10 up the series of receivers 10 collects the control signals received (via the switch 50 just mentioned) from the receiver 10 further down the series of receivers 10 and passes those control signals to the third port 56 of the switch 50 connected to that next receiver 10 up the series of receivers 10. In addition, that next receiver 10 up the series of receivers 10 may send its own control signals for the LNB 22 to retune to the third port 56 of the switch 50 connected to that next receiver 10.
This is repeated up the series of receivers 10 and switches 50 until the first switch 50₁ closest to the LNB 22 is reached. At each switch 50, control signals received via switches 50 from receivers 10 further down the series are picked up and passed on via switches 50 to the next receiver 10 up the series. For completeness and accuracy it is mentioned that the last receiver 10_n does not receive control signals from any other receivers 10 as there are no further receivers 10 below that last receiver 10_n. Likewise, the first switch 50₁ connected to the first receiver 10i sends control signals for the first receiver 10₁ and any control signals received from other receivers 10 to its first port 52 to be transmitted to the LNB 22.
In summary therefore, in this second example and similarly to the first example, each receiver 10_x passes control signals up to the next receiver 10_x-1 in the series connection to the LNB 22, albeit in this example via the respective switches 50, until the first receiver 10₁ is reached. The first receiver 10i sends its own control signal and any control signals received from receivers 10 further down the series onto the cable 30 to pass directly to the LNB 22. In this way, the control signals from the receivers 10 to the LNB 22 are not randomly or pseudorandomly sent over the single shared cable 30, which avoids collisions between the control signals from the different receivers 10.
The various commands, requests and instructions, etc. between the LNB 22 and the satellite broadcast signal receivers 10 may be in accordance with the CENELEC EN 50494 Standard, which prescribes a Digital Satellite Equipment Communications (DiSEqC 1.x) protocol for the signalling between the LNB 22 and the satellite broadcast signal receivers 10, with minor modifications as necessary in order to implement the passing of control signals in accordance with examples of the present disclosure.
It will be understood that the processor or processing system or circuitry referred to herein may in practice be provided by a single chip or integrated circuit or plural chips or integrated circuits, optionally provided as a chipset, an application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), digital signal processor (DSP), graphics processing units (GPUs), etc. The chip or chips may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor or processors, a digital signal processor or processors, baseband circuitry and radio frequency circuitry, which are configurable so as to operate in accordance with the exemplary embodiments. In this regard, the exemplary embodiments may be implemented at least in part by computer software stored in (non-transitory) memory and executable by the processor, or by hardware, or by a combination of tangibly stored software and hardware (and tangibly stored firmware).
Reference is made herein to data storage for storing data. This may be provided by a single device or by plural devices. Suitable devices include for example a hard disk and non-volatile semiconductor memory.
Although at least some aspects of the embodiments described herein with reference to the drawings comprise computer processes performed in processing systems or processors, the invention also extends to computer programs, particularly computer programs on or in a carrier, adapted for putting the invention into practice. The program may be in the form of non-transitory source code, object code, a code intermediate source and object code such as in partially compiled form, or in any other non-transitory form suitable for use in the implementation of processes according to the invention. The carrier may be any entity or device capable of carrying the program. For example, the carrier may comprise a storage medium, such as a solid-state drive (SSD) or other semiconductor-based RAM; a ROM, for example a CD ROM or a semiconductor ROM; a magnetic recording medium, for example a floppy disk or hard disk; optical memory devices in general; etc.
The examples described herein are to be understood as illustrative examples of embodiments of the invention. Further embodiments and examples are envisaged. Any feature described in relation to any one example or embodiment may be used alone or in combination with other features. In addition, any feature described in relation to any one example or embodiment may also be used in combination with one or more features of any other of the examples or embodiments, or any combination of any other of the examples or embodiments. Furthermore, equivalents and modifications not described herein may also be employed within the scope of the invention, which is defined in the claims.

Claims

A method of operating a plurality of satellite broadcast signal receivers which are connected in series to a low-noise block downconverter, LNB, of a satellite dish and which are operating according to single cable distribution, wherein a first of the receivers is closest in the series connection of receivers to the LNB and others of the receivers are further down the series connection of receivers to the LNB, the method comprising:
one of the satellite broadcast signal receivers transmitting a control signal ultimately to be received by the LNB to select a channel to be received from the LNB for said receiver;

wherein:
(a) if said one receiver is the first receiver in the series connection of receivers to the LNB, said one receiver transmits the control signal to the LNB,

(b) else if said one receiver is further down the series connection of receivers to the LNB, said one receiver transmits the control signal to another receiver that is further up the series connection of receivers to the LNB for said other receiver to pass on the control signal for the control signal to be received ultimately by the LNB.
A method according to claim 1, wherein in the case (b):
(c) if said other receiver is the first receiver in the series connection of receivers to the LNB, said other receiver transmits the control signal received from said one receiver to the LNB,

(d) else if said other receiver is further down the series connection of receivers to the LNB, said other receiver transmits the control signal received from said one receiver to yet another receiver that is further up the series connection of receivers to the LNB for said yet another receiver to pass on the control signal received from said one receiver for the control signal to be received ultimately by the LNB.
A method according to claim 1 or claim 2, wherein said other receiver transmits the control signal received from said one receiver ultimately to be received by the LNB, and said other receiver transmits its own control signal ultimately to be received by the LNB to select a channel to be received from the LNB for said other receiver.
A method according to any of claims 1 to 3, wherein:
at least some of the receivers are connected to respective switches, the switches being connected in series to each other, the switches receiving channel signals from the LNB and passing the channel signals to the receiver connected to the switch and/or down the series of connected switches to be passed to the receivers respectively connected to the switches in accordance with the channel(s) selected by the respective receivers.
A method according to claim 4, wherein the switches are arranged to receive control signals transmitted by the receiver connected to the switch;
wherein the switch that is connected to the first receiver in the series connection of receivers is connected to the LNB to pass control signals to the LNB and to receive channel signals from the LNB, each other switch being connected to the receiver that is further up the series of receivers and operating to pass control signals received at the switch to said receiver that is further up the series of receivers for said receiver.
A method according to any of claims 1 to 5, at least some of the receivers having a wireless connection to a receiver that is further up the series of receivers for wirelessly transmitting control signals up the series of receivers.
A switch for use in a single cable distribution system in which a plurality of satellite broadcast signal receivers are connected in series to a low-noise block downconverter, LNB, of a satellite dish to receive channel signals from the LNB, the switch comprising:
a first port for receiving channel signals;

a second port for connecting the switch to the first port of another switch to pass channel signals for other receivers received at the first port of the switch to said first port of said other switch;

a third port for connecting the switch to a satellite broadcast signal receiver to pass channel signals for said satellite broadcast signal receiver to said satellite broadcast signal receiver and to receive control signals from said satellite broadcast signal receiver; and

a fourth port for connecting the switch to another satellite broadcast signal receiver that is further up the series connection of receivers to pass control signals to said other satellite broadcast signal receiver;

the switch being constructed and arranged such that:
channel signals received in use at the first port and intended for a receiver connected in use to the third port are passed to said receiver connected to the third port;

channel signals received in use at the first port and intended for another receiver are passed to the second port to be passed to the first port of another switch;

control signals received in use at the third port are passed to the fourth port to be passed in use to another satellite broadcast signal receiver that is further up the series connection of receivers if the fourth port is connected to another satellite broadcast signal receiver; and

control signals received in use at the third port are passed to the first port to be passed in use to a said LNB if the fourth port is not connected to another satellite broadcast signal receiver.
A satellite broadcast signal receiver for use in a single cable distribution system, the receiver comprising:
a channel signal input through which channel signals can be received from a low-noise block downconverter, LNB, of a satellite dish;

a control signal output through which control signals for a said LNB can be passed to select a channel to be received from a said LNB for the receiver; and

a control signal input through which control signals for a said LNB from other satellite broadcast signal receiver can be received;

the receiver being constructed and arranged such that if the receiver is not the first receiver in the series connection of receivers to a said LNB, then the receiver transmits control signals through its control signal output to be received at a control signal input of another receiver in the series connection of receivers to a said LNB for said other receiver to pass said control signals on, the control signals including control signals to select a channel to be received from a said LNB for the receiver, and the control signals including control signals to select a channel to be received from a said LNB for other receivers further down the series connection of receivers and received a the receiver;

the receiver being constructed and arranged such that if the receiver is the first receiver in the series connection of receivers to a said LNB, then the receiver transmits control signals to the LNB, the control signals including control signals to select a channel to be received from a said LNB for the receiver, and the control signals including control signals to select a channel to be received from a said LNB for other receivers further down the series connection of receivers and received a the receiver.
A receiver according to claim 8, wherein the control signal input and the control signal output provide for wireless communications from the receiver to another receiver.