AU2009250973A1 - Termination - Google Patents

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant (s) : C10 Communications Fty Ltd Invention Title: TERMINATION The following statement is a full description of this invention, including the best me thod for performing it known to me/us: TERMINATION Field of the Invention s The present invention generally relates to a termination for a terminal of a telephone network, and particularly but not exclusively to a termination for a telephone terminal of a network carrying a high frequency signal such as a VDSL signal. 10 Background of the Invention Asymmetric Digital Subscriber Line (ADSL) provides digital data transmission over public switched telephone is networks (PSTN), for example, to premises such as a house, unit, office or building 10 as shown in Figure 1. The premises 10 has existing telephone wiring 12 in the form of a network. In this example, the network 12 is a star network although other configurations, such as daisy 20 chain, are possible. The network 12 has an input 14 which is used to connect the network 12 to a telephone exchange (not shown). A voice 16 and a digital ADSL signal 18 from the exchange is launched into the network 12 via the input 14. The voice signal occupies a low frequency band of the 25 signal and the digital ADSL signal occupies a higher frequency band of the signal. The network 12 has terminals such as 20 and 22 which are typically telephone sockets mounted to walls or other surfaces present at the premises 10. To connect either a telephone or an ADSL 30 modem to one of the terminals, such as 22, a filter 24 is typically connected to the terminal 22 which splits the low frequency voice signal from the high frequency data signal and directs the low and high frequency signals to 21486_SS1 (ICHM4ut - 3 respective sockets to which the telephone 26 and modem 28 can be connected. Figure 2 shows another representation of the network 12 configured for ADSL. There is no pressing reason to terminate any unused terminals such as s terminal 20. It is desirable to replace an ADSL service with a potentially much faster Very high rate Digital Subscriber Line (VDSL) service or a similar high speed service. VDSL 10 uses frequencies up to 17.664 MHz in one standard and 30 MHz in another which are much greater than the maximum frequency of ADSL. The ADSL 2+ standard has a maximum frequency of 2208 kHz, ADSL 2+ being a faster type of ADSL. The high frequency components of a VDSL signal 15 behave very differently in a network, such as 12, than the relatively low frequencies of ADSL 2+, for example. A wiring segment, such as 30 in Figure 1, will act like a transmission line to a frequency component of a 20 signal having a characteristic frequency f if the length of the wiring segment is of the same order of magnitude or greater than the corresponding wave length. The wave length X is given by 25 = clef (1) where c is the speed of light, f is the signal frequency and e is the effective dielectric constant of the insulation in the house wiring segment. A typical house 30 wiring segment such as 30 has the length of the order of 10 metres, and applying equation (1) for ADSL results in a wave length generally much greater than 10 metres and thus transmission line effects are negligible. At VDSL frequencies, however, the wave length is of the order of a typical house wiring segment and the transmission line properties of the segment need to be accounted for. 5 A transmission line requires matching of source, line and termination impedances otherwise deleterious effects are manifest. For example, if the impedances are not matched, part of the energy traveling down the transmission line may be reflected and interfere with the 1o incoming signal. When several terminals exist in a premises 10, such as 20 and 22, it is not uncommon to find one of the sockets, such as 20, unterminated. Alternatively, is telephone equipment such as a telephone may have a very high impedance. Unterminated sockets and/or high impedance equipment require proper termination of the high frequency VDSL service component on the network 12. 20 Unfortunately, it is generally considered impossible to find a suitable termination for any free terminals which would prevent reflections and also provide a suitable network input impedance at the input 14. The current solution is to install a central filter at the 25 input 14. While a central filter gives the best result, expensive and inconvenient professional installation is often required and an extra cable may be required between the central filter and the modem, which may require modification of the premises 10. 30 24tRit_1 (GRHMatters) -5 Summary of Invention According to a first aspect of the invention there is provided a device comprising; s a plug configured to be inserted into one of a plurality of telephone sockets of a premise's telephone network; and a termination having compromise matching impedance for a high frequency data signal transmitted on the 10 telephone network, the compromise impedance ameliorating any mismatch effects of the telephone network on the data signal. The compromise impedance is not an exact matching 15 impedance for the system, but nevertheless still operates to reduce the effects of any mismatch effects on the data signal. In an embodiment, the termination comprises a 20 capacitance and a resistance- The termination may comprise a capacitor, and a resistor in series. Alternatively, the termination may comprise a capacitor, a resistor and another capacitor in series- In still another alternative, the termination may comprise a resistor, a 25 capacitor and another resistor in series. The capacitance may be greater than 0-1 nF and less than 100 nP. Alternatively, the capacitance may be in the range of 2.2 nF to 10 nF. The resistance may be greater than 110 Ohms and less than 200 Ohms- Alternatively, the resistance may 30 be around 120 Ohms- Alternatively, the resistance may be around 150 Ohms. In an embodiment, the device comprises a housing in which the termination is housed. The plug may be proximal 35 to the housing. Alternatively, the housing may be at least part of the plug. 2146S35_ (CHMwm) In an embodiment, the termination provides compromise matching impedance for a VDSL signal transmitted on the telephone network 5 In an embodiment, the plug is a -600 series plug, such as a 604 or 606 plug. In an embodiment, the plug has 2 or more pins and the 10 termination connects at least 2 of the pins. The plug may be a RJ1l plug and the termination connects pin 2 and pin 3 of the plug. Alternatively, the plug is RJ45 plug and the termination connects pin 4 and pin 5 of the plug. is In an embodiment, the device is configured to block further connection to a socket it is plugged into. In an embodiment, the device further comprises one or more sockets in electrical communication with the plug. 20 One or more of the sockets may be proximal to the housing. Alternatively, the one or more sockets form respective recesses in the housing. The sockets may each be either a modular socket or a 600-series socket such as a 610 socket. The device may comprise a double adaptor. The 25 sockets of the double adaptor may be different types. According to another aspect of the invention there is provided a wall socket for a premise's telephone network, the socket comprising a termination having compromise SC matching impedance for a high frequency data signal transmitted on the telephone network, the compromise impedance ameliorating any mismatch effects of the telephone network on the data signal. 35 In an embodiment, the termination comprises a capacitance and a resistance- The capacitance may be greater than 0.1 nF and less than 100 nF. The capacitance 21466M3 , (GHMatt-j - 7 may be in the range of 22 nF to 10 nF. The resistance may be greater than 110 Ohms and less than 200 Ohms. The resistance may be around 120 Ohms. The resistance may be around 150 Ohms. 5 In an embodiment the socket is a 600 series socket, such as a 610 socket. In an embodiment, the socket has 2 or more pins and io the termination connects at least 2 of the.pins According to a third aspect of the invention there is provided a termination configured to be coupled to one of a plurality of telephone sockets of a premise's telephone is network, a termination having compromise matching impedance for a high frequency data signal transmitted on the telephone network, the compromise impedance ameliorating any mismatch effects of the telephone network on the data signal. 20 Brief description of the Figures In order to achieve a better understanding of the nature of the present invention embodiments will now be 25 described, by way of example only, with reference to the accompanying figures, were similar components are similarly numbered, in which: Figure 1 is an example of a network which receives both voice and ADSL data according to the prior art; 30 Figure 2 shows an equivalent representation of the network shown in Figure 1; Figure 3 shows one example of a termination used in a network that receives VDSL data; 274Gf351 (GHMmrttes) - 8 Figure 4 shows another example of a termination in the form of a plug, and a socket or jack the plug may be received by; Figure 5 shows another example of a device having a 5 plug configured to be inserted into one of the plurality of telephone sockets of the premises' telephone network, the device having a termination having comprised matching impedance, and also having a socket for connection to a telephone handset, for example; 10 Figure 6 shows another embodiment of a device similar to that of Figure 5; Figures 7 and 7a show other examples of devices having a comprise termination but configured to have multiple sockets to act as a double adaptor for is simultaneous connection of, for example, a telephone handset and a facsimile machine; Figure 8 shows a device similar to that shown in Figure 5 but having 600 Series plug and socket; Figure 9 shows a similar device to that shown in 20 Figure 6 but having a 600 Series plug and a modular socket; Figure 10 shows a device similar to Figure 8 but having a 600 Series plug, a modular socket and also a Series 600 socket; 25 Figure 11 shows an example of a socket having the termination in the form of surface mount components soldered in place; Figure 12 shows one example of a 600 Series wall socket (with cover removed) having a termination 30 comprising a capacitor and a resistor connecting pins of the socket; 214555_1 (GHMattr) Figure 13 shows both the termination shown in Figure 3 and another example of a termination used in another example network that receives VDSL data; Figure 14 shows a simulated circuit used to 5 demonstrate the effectiveness of the terminations of Figures 3 and 4; and Figures 15 and 16 show the input impedance as a function of frequency of the simulated circuit of Figure 5 both with and without termination. 10 Detailed Description of embodiments of the invention Figure 3 shows a circuit schematic of one embodiment of a termination 32 arranged to be connected to a terminal is 20 of a network 12- In this example, the network is a home telephone network but it could be a network in any suitable premises. The network 12 has output terminals 20 and 22. The network also has an input 14. A signal from a telephone exchange (not shown) is launched into input 14 20 for propagation along the network 12 to the output terminals_ In this embodiment, the signal comprises a low frequency analogue voice signal 16 and a high frequency data signal 18. The high frequency data signal is, in this example, a VDSL signal although other high frequency 25 signals may be substituted. In the context of this specification, a signal is considered to have a high frequency if the network displays transmission line effects for at least part of the signal. The termination 32 has an impedance which ameliorates reflection of the 30 signal at terminal 20. In this example, the termination also has an impedance that provides an input impedance at the input terminal 14 in concordance with a nominal input impedance of the network 12. The nominal input impedance - 10 is typically a characteristic impedance of the telephone cable constituting the network 12, which is typically 100 Ohms at VDSL frequencies. While it is difficult if not impossible to provide an ideal termination to prevent s reflections and the correct input impedance, this embodiment of a termination provides a compromise termination- A higher than 'ideal' 100 Ohm termination is used to partially absorb reflections at the terminals, while the input impedance is lower - but not 10 catastrophically so - than the perfect input impedance also of 100 Ohms. However the overall performance is significantly improved over no termination. The termination 32 may be housed in a convenient form is such as a plug 31 arranged to connect to a telephone socket 33 as shown in Figure 4. The plug and socket may belong to a standard such as, a 600 series, or modular (RJ45 or RJll typically)) standard- In the case of RJ45 telephone plugs and sockets, for example, the termination 20 may comprise a compact surface mount resistor and capacitor(s) to fit within these small connectors. In the case of the device 31 shown in Figure 5, when the device 31 is inserted in the socket 33 the accessible 25 end 33 does not provide a socket to plug further devices such as a telephone handset into. In this example, the device is configured to block further connection to the socket 33 when it is plugged into the socket 33 so In other examples, such as that shown in Figure 5 however, the device 60 has both a plug 66 and a socket 68. The device has a housing 62 in which the termination 64 is housed. Plug 66 is configured to be inserted into a 214e35,,I (GHM.rs) - 11 telephone socket. In this example, the plug 66 is proximal to the housing 62. In this example, the plug 66 is attached to the housing 62- In some alternative examples, however, the plug and socket are separated by a s cable connecting them. A termination 64 is connected to 2 pins of the plug forming an electronic bridge between them. In the case of a RJ1l plug, the termination connects pins 2 and 3 of the plug. Alternatively, in the case of a RJ45 plug, the termination connects pins 4 and 5 10 of the plug. In alternative embodiments, the termination 64 may be housed within the plug 66 and thus the telephone plug is in effect the housing or at least part of it. The device 60 of Figure 5 also has a socket 68- The socket 68 is recessed into the housing 62. The socket 68 is in 15 electrical communication with the plug 66 so that a signal in the voice band can pass through the plug out of the socket to a connected device such as a telephone handset or facsimile machine. The termination 64, however, properly terminates the high frequency data signal. 20 The use of device 60 in Figure 6 is advantageous as it requires no skill and is quick to install, and provides termination of a VDSL signal with or without a telephone plugged into it. The telephone can be unplugged and 25 provided the device 60 is retained by the socket the termination is still provided. The user can simply insert the plug 66 into the wall socket and then connect the telephone or other low frequency device such as a facsimile to socket 68. The socket is then terminated 30 with an appropriate compromise termination 64 for the high. frequency data signal while allowing the low frequency telephone signal to leave the socket 68 and proceed to the telephone handset. The device 60 is compact, easy to - 12 install, and an extra device that splits the high and low frequency signals to different sockets is not required. The device 60 may be cheap to manufacture. The device is especially compact when the plug 66 is proximal to the s housing 62 or when the plug 66 itself housing houses the termination 64. Figure 6 shows another example of a device 70 similar to device 60 of Figure S. The device 70 has a housing 72 10 and a plug 76 attached to the housing 72 and proximal to it. Device 70 also has a socket 78 in communication with the plug 76. Inside the housing 72, and obscured from visibility, is a termination. 15 Figure 7 shows another example of a device 80 having a modular plug 86 and a housing 82. The device 80 has 2 modular sockets 78 and 79. The device in Figure 8 is in the form a double adaptor. A fax, for example, can be connected to one socket 79 and telephone to the other 20 socket 78, for example. Alternatively, two handsets may be connected- The device 80 has a termination which is not visible. Figure 7a shows a similar device 81 to device 80 but having 600 Series connections. 25 Figure 8 shows another example of a device 90 having a plug 92 and a socket 94. The device 90 has a housing 82 which houses a termination. The device in Figure 8 has 600 Series plug 92 and socket 94 rather than modular plug and socket. Generally, any type of suitable plug or 30 socket can be used. Figure 9 shows a device similar to that in Figures 6 and 8 except the plug and socket are different types. The 21415l1 (GHM5rrrs) -13 plug 102 is a 600 Series plug and the socket 104 is a modular socket. It has a termination Figure 10 shows a double adaptor of similar function s to that as device 80 in Figure 7. The device 110 has a 600 Series plug 102, a modular socket 114 and also a 600 Series socket 116- The device 110 of Figure 10 is a double adaptor- It also has a termination 10 In some other embodiments, however, the termination may be included inside a socket installed in the home (mounted to a wall, for example) and arranged for a telephone or other voice-band device to be connected thereto. The termination terminates the VDSL signal is without interfering with the voice signal. Figure 11 shows a wall socket 200 which in use is mounted adjacent to or in the wall of a premises and provides an output socket 204 for the telephone network of 20 the premises- The outer housing has been removed so the internals are visible in the picture. The wall socket 200 has a modular plug 204 for the connection of low frequency devices such as a telephone handset or facsimile machine. A termination 206 bridges conducting tracks 208 and 210 25 each connected to respective pins of the socket 204. The termination comprises a capacitance and a resistance, provided by a capacitor and resistor. Figure 12 shows another example of a wall socket 210 30 in the form of a 600 Series wall socket- The socket 210 has a resistor 212 and capacitor 214 connected in series and bridging a pin 216 to another pin 218 of the wall socket 210. The wall socket may be a conventional wall 21MPW5Z (GHMUMmr) - 14 socket that has been retro fitted with the termination, or alternatively wall sockets may be manufactured with the termination S Terminating a terminal such as 20 with a purely resistance impedance is not acceptable because a telephone line would then be permanent looped. Thus the termination has high frequency and weak AC coupling- Since the long line effects and reflections are typically in the MHz io frequency range, an impedance may be connected to the line using a high frequency coupling that only affects the MHz range. The termination 32 is arranged not to influence DC or is the low frequency audio signal. However, the high frequency VDSL signals are at least in part terminated to prevent strong reflections at terminal 20. The termination 32 comprises a capacitor 34, a 20 resistor 36 and an another capacitor 38 in series (C-R-C) and in that order. However, the circuit may not necessarily be balanced. One of the capacitors 34 may be omitted (C-R). Alternatively, a R-C-R series may be used The termination 32 electrically joins two paired elongate 25 conductors 40 and 42 which together constitute one of the cables comprising the network. In this embodiment, the capacitor 34 has the same value as capacitor 38 although it need not be so. The impedance of the termination, in this example, is predominantly non-reactive such that the 30 magnitude of the real part of the impedance is ruch greater than the magnitude of the imaginary part of the impedance. 214WO.'1 GM~ .Lurr: - 15 The characteristic impedance at VDSL frequencies is generally considered to be 100 Ohms but this may vary with frequency. Since the VDSL modem 28 already terminates terminal 22 at 100 Ohms, adding the same value at terminal 5 20 would double terminate the network 12 and result in low input impedance at 14- It should be noted however, that even double termination (or greater) may be substantially better than no termination at all depending on the circumstances- Generally, a better value for resistor 36 10 is greater than 100 Ohms, the characteristic impedance. While there is no theoretical upper limit, measurements have shown that a resistance greater than about 3 to 4 times the characteristic impedance of 100 Ohms has a small effect in improving performance of receiving and sending is VDSL across a network such as 12. Table 1 tabulates the results of VDSL speed testing for segment (stub) lengths of 5, 10 and 15 metres and terminations having a resistance of 100 Ohms, 120 Ohms, 20 150 Ohms and 270 Ohms. The maximum speed achieved for each termination in both upstream and downstream directions is shown in bold text. For segment lengths of a round 5 to 10 metres the 120 Ohms resistor was found to provide near maximum VDTJSL speeds- Values between 110 and 25 130 Ohms may be suitable. For a longer length of around 15 metres, a higher resistance of around 150 Ohms was found to be better. Values between 140 and 160 Ohms may be suitable. From these results it may be concluded that a resistance greater than 110 Ohms and less than 200 Ohms ao is a good choice if the segment length is not known in advance. However, for shorter segments such as 5 metres a resistance of around 120 Ohms appears to be preferable 2146625 1 (GHMutter6) - 16 while for longer segment lengths of around 15 metres resistances of around 150 Ohms seems preferable. Various capacitances have been tried and generally a s capacitance in the approximate range of 2 nF to 10 nF is found to display desirable results although a capacitance anywhere between 0.1 nF and 100 nF may still be acceptable in some applications. 10 TABLE I; VDSL speed tests for various reSistanCes. VDSL speed testing Speed kbps 15 Aug. 2008 Line length: 340m with stub:! 5m n10' Ism Upstream Downstream Upstream Downstream Upstream Downstream Termination: Open 37630 72020 43048 76388 43056 79496 270 ohm 42464. 87664 150 ohm 43644 8841.2 .44040. 90772 44934 98972 120 ohm 44032 92295 44452 98972 44456 89728 100 ohm 40700 74340 42850 78516 43582 82532 To estimate an appropriate lower bound value for the capacitor, we note that an RC circuit has a high pass is characteristic with the following cut off frequency: f = 1/2fRC (2) The lower limit for the frequency could be, for example, 1 MHz, which would correspond to quite a long 20 wiring segment. For R=100 Ohms and f = 1 MHz we find that each capacitor should have a capacitance of 0.32 nF as a minimum value. That is, the terminator 32 with capacitors of this value will appear absent for low frequencies, where the network 12 does not behave as a transmission 25 line, but the high frequencies would be coupled across the resistor 36 for at least partial termination- Generally, a higher than minimum value for the capacitors may be 214O53L1 (GiMtWer) - 17 used- The maximum value for the capacitors can be estimated from the condition that the capacitor exhibits a high impedance at low frequencies. The capacitive reactance is given by S Xc = 1/2fC (3) In this equation f =4 kHz, which is generally the highest voice frequency. By choosing Xc = 10 kOhm as a 10 minimum impedance we get a maximum value of capacitance for each capacitor to be 8 nF In some embodiments, the capacitive coupling is replaced by an inductive coupling. This type of coupling is is also be active only in AC and will not create a DC loop on the line. Resistive range is in the same range as the above example. The inductive coupling has to become significant at frequencies in the order of 1 MHz and above and should be insignificant at lower frequencies. 20 Figure 13 shows another embodiment of a network generally indicated by the numeral 44, the network 44 having three terminals. Terminal 20 is terminated in the similar manner as for Figure 3. Terminal 22 has a filter 25 24 connected thereto for splitting low frequencies to a telephone 26 and high frequencies to a VDSL modem 23 with 100 Ohm internal termination. The filter 24 has two inductors in a balanced circuit arrangement, to be connected to the telephone line, to achieve the split. 30 The network 44 also has a third terminal 45- To this terminal is attached a filter 48 which directs low frequencies to a telephone 26. The high frequency VDSL signals are not used at terminal 45 and thus a high 2146635.1 (GHM46rA) - 18 frequency port or socket 50 of the filter 48 is connected to a termination 32 similar or identical to termination 36. This termination 32 may be either external to the filter and housed in a plug compatible with a socket of a s filter 50 or otherwise built inside the filter 48. In this latter case, there is no need to include port 50. Even if a socket does not have any telephone equipment connected, it may still need a filter to terminate the VDSL signal. The plug may be received by a wall socket if 10 unused. In order to demonstrate the effectiveness of the termination, the circuit 60 shown in Figure 14 was measured. The circuit 60 simulates a main telephone cable 15 branching off into two lines of length 10 metres and 15 metres respectively- The 10 metre section is terminated by a 100 Ohm resistor R12 equivalent to a matching impedance by a VDSL modem, while the 15 metre section may be left open or terminated by a 300 Ohms resistor R2. The 20 signal generator 52 simulates a data signal. In this case, as there is no voice signal the termination capacitors are omitted. Figure 15 shows impedance seen by the signal generator 52 over the frequency range of 1 MHz to 30 MHz with R2 absent- It can be seen that there is a 25 large variation of impedance and there are frequencies where the impedance is very low - effectively a short circuit. In this case, the input impedance drops to 0, that is effectively a short circuit at approximately 2% MHz, 7% MHz, 12% MHz and 17% MHz. These frequencies are 30 thus unusable and the VDSL signal substantially corrupted When there is partial and correct termination as shown in Figure 16, that is the resistive load is higher than the required matching impedance, the line is not perfectly 2145u-l (Gm M..t.er: - 19 terminated-hut the reflections are vastly reduced and the nulls in the input impedance are no longer present. There is less impedance variation and the impedance does not drop to 0. This is a very substantial improvement on the 5 situation shown in Figure 15 and only modest drops in transmission efficiency are expected in this case. Now that embodiments have been described, it will be appreciated that some embodiments have some of the io following advantages: A VDSL service can be provided to a premises with an existing telephone network, such as a phone, without installation of a central VDSL filter; A socket can be terminated quickly by an unskilled is person by plugging in a device with termination rather than having a technician install a termination at the socket or alternatively installing a central filter; and A dedicated filter/splitter may be substituted for a simpler, cheaper and more compact device at sockets that 20 are not connected to a modem. It will be appreciated that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the 25 spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. In the claims which follow and in the preceding 30 description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, 2143CMj(GP l ) - 20 i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. 5 It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country. 10 2!4 635_1 (GHM ers)

Claims (21)

1. A device comprising: a plug configured to be inserted into one of a s plurality of telephone sockets of a premise's telephone network; and a termination having compromise matching impedance for a high frequency data signal transmitted on the telephone network, the compromise 10 impedance ameliorating any mismatch effects of the telephone network on the data signal.

2. A device defined by claim 1 wherein the termination comprises a capacitance and a resistance. is

3. A device defined by claim 2 wherein the termination comprises a capacitor, and a resistor in series

4. A device defined by claim 2 wherein the termination 20 comprises a capacitor, a resistor and another capacitor in series.

5. A device defined by any one of claims 2 to 4 wherein the capacitance is greater than 0.1 nF and less than 25 100 nF.

6. A device defined by any one of claims 2 to 4 wherein the capacitance is in the range of 2.2 nF to 10 nF. 30 7. A device defined by any one of claims 2 to 6 wherein the resistance is greater than 110 Ohms and less than 200 Ohms.

8. A device defined by any one of claims 2 to 6 wherein 35 the resistance is around 120 Ohms. 2t466351 (GHMor.) - 22 9. A device defined by any one of claims 2 to 6 wherein the resistance is around 150 Ohms

10- A device defined by any one of the preceding claims s wherein the device comprises a housing in which the termination is housed.

11- A device defined by claim 10 wherein the telephone plug is proximal to the housing. 10

12. A device defined by claim 10 wherein the housing is at least part of the plug.

13- A device defined by any one of the preceding claims 15 wherein the termination provides compromise matching impedance for a VDSL signal transmitted on the telephone network.

14. A device defined by any one of the preceding claims 20 wherein the plug is a 600 series plug.

15. A device defined by any one of the preceding claims wherein the plug has 2 or more pins and the termination connects at least 2 of the pins. 25

16. A device defined by any one of the claims I to 13 wherein the plug is a PJ11 plug and the termination connects pin 2 and pin 3 of the plug. 20 17. A device defined by any one of the claims 1 to 13 wherein the plug is RJ45 plug and the termination connects pin 4 and pin 5 of the plug.

18- A device defined by any one of the preceding claims 35 configured to block further connection to a socket it is plugged into. 214663rl (CGHMatterg - 23 12- A device defined by any one of claims 1 to 17 further comprising one or more sockets in electrical communication with the plug. s 20. A device defined by claim 19 wherein the sockets may each be either a modular socket or a 600-series socket.

21- A device defined by either claim 191 or 20 comprising 10 a double adaptor.

22. A device defined by claim 21 wherein the sockets of the double adaptor are different types. 1s 22. A wall socket for a premise's telephone network, the socket comprising a termination having compromise matching impedance for a high frequency data signal transmitted on the telephone network, the compromise impedance ameliorating any mismatch effects of the 20 telephone network on the data signal.

24. A wall socket defined by claim 23 wherein the termination comprises a capacitance and a resistance. 25 25. A wall socket defined by claim 24 wherein the capacitance is greater than 0.1 nF and less than 100 nF.

26. A wall socket defined by claim 24 wherein the 30 capacitance is in the range of 2.2 nF to 10 nF.

27. A wall socket defined by any one of claims 24 to 26 wherein the resistance is greater than 110 Ohms and less than 200 Ohms.

35. 28. A wall socket defined by any one of claims 24 to 26 wherein the resistance is around 120 Ohms. - 24 29. A wall socket defined by any one of claims 24 to 26 wherein the resistance is around 150 Ohms 5 30. A wall socket defined by any one of claims 23 - 29 wherein the socket is a 600 series socket. 31- A wall socket defined by any one of claims 23-30 wherein the socket has 2 or more pins and the 10 termination connects at least 2 of the pins. 32. A device defined by claim 2 wherein the termination comprises a resistor, a capacitor, and another resistor in series 15 33. A termination configured to be coupled to one of a plurality of telephone sockets of a premise's telephone network, a termination having compromise matching impedance for a high frequency data signal 20 transmitted on the telephone network, the compromise impedance ameliorating any mismatch effects of the telephone network on the data signal. 34. A device defined by claim 1 and substantially as 25 herein described with reference to Figures 3 to 16. 35. A wall socket substantially as herein described with reference to Figures 3 to 16. 30 36. A termination substantially as herein described with reference to Figures 3 to 16.