CA1237780A - Radio communications system eith randomly scattered, automatically organizable relay stations - Google Patents
Radio communications system eith randomly scattered, automatically organizable relay stationsInfo
- Publication number
- CA1237780A CA1237780A CA000485207A CA485207A CA1237780A CA 1237780 A CA1237780 A CA 1237780A CA 000485207 A CA000485207 A CA 000485207A CA 485207 A CA485207 A CA 485207A CA 1237780 A CA1237780 A CA 1237780A
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Abstract
Abstract of the Disclosure A fully distributed, disposable, self-organizing, independently powered communications system, capable of providing a radio-communications channel in environments that may prove dangerous or inaccessible to humans and that may be hostile to communications systems, comprises a number of randomly scattered self-contained relay transceiver stations which automatically organize themselves to form a relay chain capable of transporting radio messages between two user terminal stations as long as the distance between the user stations is bridged by the relay stations in line-of-sight proximity with each other.
Description
1;~,3 .' This invention relates to digital communications systems and,rnore part-ocularly, to a fully distributed, disposable, self-organizing, self-powered soys-tent which can be deployed, activated, operated and maintained in a hostile en-vironment without the need for human assistance.
As is well known and understood, a wide variety of problems come into play in operating a radio-con~Lnicatic~s systent in a hostile environment. For example, r,tessage traffic flow from user to user and from node to node or front relay station to relay station is usually controlled by centralized units which l are of far higher corrtplexity, value, weight and bulk than the relay or user stay 1 lion. In digital communications systems this centralized unit frequently is acornputer Lucia operates together with a large collection of peripheral equipment This means that the whole system is hierarchically organized such that the open atonal availability of the whole system depends on the availability of the highest member in the hierarchy, the central control unit. ~orneone who is in-terested in deactivating the system only has to concentrate his efforts on de-activating the central control unit . Isles task is simplified by the fact that these units are much easier to detect and easier to destroy than the lower and more expendable members of tile hierarchy.
l Also contributing to problems in their usage, such conrnunications soys-1 terms most often operate at UHF frequencies, where tall antenna structures arereouired for line-of-sight transntissions -- especially in wooded areas and in localities where other obstructions such as buildings predominate. ugh antenna structures increase system vulnerability to detection, electrical interference I and physical destruction.
J
lath the tecttnolo~y frequently e cloyed in their construction, no will-the manners of their implementation, such communications systems offer further disadvantages in that their component parts have to be repaired, replaced and maintained -- because of their expensive costs and non-disposability. This leads to additional problems by requiring a dedicated supply, storage and no-pair organization whose own limits in availability contribute to limits in soys-them survivability.
In order to make a communications system less detectable one has to oh-sure its appearance. While nothing can be done to reduce a given physical size, one can try to hide system units, e.g., in natural or man-made cover and one can give its electrical emissions a noise-like appearance, e.g., by spread-in its electrical emissions over a large frequency range by so-called spread-spectrum methods. However, physical hiding interferes with loneliest open-anion and spectrum spreading increases the cost, complexity and, hence, the physical bulk of the system units.
In order to make communications and communications systems less vulner-able one usually tries to supply a sufficient number of back-up copies of soys-them units and messages, i.e., one increases redundancy. This again can only be bought at higher costs and complexity or one has to accept a decrease in system performance by only partly utilizing the system, i.e., by slowing down or reducing the message traffic.
Other disadvantages of such prior art communications systems will also be readily recognized: a) The high cost involved because of limited product lion runs; b) The continuing use of increasingly obsolete designs so as not to incur the additional costs of new developments; c) The high degree of train-in required in the utilization of the communication equipments; d) The Defoe-gully in transporting about, because of weight, size and bull.
s will become clear hereinafter, the electronic communications and con-trot system of the invention comprises a fully distributed, disposable, self-organizing, self-powered communications system. when deployed, it will paraffin its junctions by simultaneously maximizing the survival of the system under all foreseeable threats during the time interval in which the system is needed. As will be seen, the communications system operation entails the randomly seeding of an area with system units.
ore specifically, as will become clear from the following description, these system units are each small, disposable transceivers, which are self-powered, and which include a defined amount of built-in digital processing llcapability. Preferably contained on a monolithic semiconductor chip utilizing livery low power technology, these transceiver units would be powered by a suitable energy storage device such as a capacitor or a plastic-encased thick film or gel ¦
battery which could be made rec~rgeable by a battery of solar cells.
in a preferred embodiment, the entire transceiver unit is attached to a¦
piece of thin plastic material, which can then be deployed as easily as anti radar "chaff", e.g., by airplane (drone), rocket, balloon or barreled weapon. The plastic film is to be shaped in such a way that it will become entangled in obstacles such as tree foliage and/or other ground cover. The plastic film is additionally to serve as the base material for an appropriate I printed antenna structure -- with the carrier frequency being such as to allow llline-of-si8ht operation, even in wooded areas, and preferably outside the established capabilities of a potential jammed, or at least in a range where an attempted jamming would require a large investment in equipment usage and power dedication. A suitable carrier frequency, according to the invention, would be at, or above, 12 I and in the interest of power conservation a pulsed carries is to be used, with modulation being combined with suitable spread-spectrum schemes if needed.
In accordance with a preferred form of the invention, system operation ., , 77~
is initiated by random distribution of system elements over an area which bridges the distance between two, or more, operating tenmm at stations. Such terminal stations may be of the type including commutlicatiatls stateless, sensor elements, remotely activated or operating electronic systems, or remotely anti-voted or operated automata or robot systems, with the system elements being de-plowable either before, or after, the terminal stations have been established.
As will be seen, such system elements may even "wait" in a dormant state in some potentially hostile territory, until being called into action.
The system is a homolog~te by virtue of the fact that all system units are of exactly similar construction with similar operational capabilities.
There is no hierarchical organization whatsoever s will be readily understood by those skilled in the art, the dispose able transceiver system elements can be recruited into the cumm~nications net-Turk by call signals issued by the terminal stations, requesting access to the network. Those system elements nearest to a terminal station would then no-spend to the call, and relay it to the system elements nearest to them, and so on. When a call finally reaches its destination, all disposable transceiver system elements which have contributed to the linlcing of the two stations to-getter Toledo then became "members" of a particular data path; all other disk potable transceiver system elements which have not yet achieved such a linking would "drop out", and return to the standby wait for reception of the recruit-in call mode. In furtherance of the system network, different operating and control modes -- as well as terminal stations and system element identifiers -- will be seen to be represented by suitable codes established in accordance with an operations protocol.
The way in which system elements contact each other can be thought of as being similar to the way in which data-processing elements in living systems nerve cells, contact each other through their synapses.
These and other features of the present inverttion will be more clearly , 1,~.~,3'~.t~
understood from a consideration of the following description, taken in connect lion with the accompanying drawings in itch:
FIGURE 1 is a functional block diagram of the electronic communications and control system transceiver element according to the invention;
FIGURE 2 illustrates a suitable packaging for tile transceiver system element as will permit easy deployment by airplane, rocket, balloon, barreled weapon or other suitable deployment c~lveyance;
FIGURE 3 is a block diagram, in implied form, of a terminal station as might be employed in the system operation;
¦ FIGURE 4 is a block diagram illustrating the addition of further terming Sal station equipment for employing the disposable transceiver system elements in a multi-channel operation, for example, and in a communications nitric to be compatible with other, different communications formats and systems; and FIGURES 5-10 are flow diagrams useful in an understanding of the present invention.
As the communications and control system of the invention can be viewed as a multiple electronically synapsing homology the system description and come pennants will, for the sake of siinplicity, be hereinafter referred to by the acronym MESH. Thus, referring to the block diagram of the MUSH unit of FIGURE
1, reference numeral 10 identifies the central processing unit, which, through its inpu~/output circuit 12 controls all unit functions. The programs for all its modes and, in the case of connected terminals all interfacing characters-tics, are shown to be stored in a read-only memory 14. Temporary storage for the processing functions and message buffering is available in a random access n or 16 and in a stack of registers (not shown). All timing functions -- as well as frequency synthesis -- are controlled by a master clock 18.
In the receiving mode, the antenna 20, through the antenna switch 22, is connected to the receiver 24, which derives its local oscillator frequency prom the frequency synthesizer 26. The received signal is demodulated in the 1~771~
demodulator 28, from where it is routed to the central processing unit 10 through the input/output circuit 12. In the transmitting mode, the transmitter switch 30, under program control from the central processing unit lo (through the input/output circuit 12), switches on the modulator 32 and the transmitter 34, and connects the antenna 20 to the transmitter output by means of the an-henna switch 22. The processed base band signal from the central processing unit lo is applied, also, to the modulator 32 by means of the input-output circuit 12, with the modulator 32 then supplying a modulated intermediate ire-quench to the transmitter 34 whose carrier frequency is supplied, or ccntrolledJ
lo by the frequency synthesizer 26. A temperature drift, affecting clock frequent cry, would thl~sly have the same direction of deviation in the transmitter 34 as well as in the local oscillator, and, hence, the receiver tuning frequencies of all ASH units deployed in the same envirc~ment would have the same direct tonal deviation It is, of course, possible to improve the basic clock stay ability by bonding the substrate of the integrated circuit to a material whose thermal expansion counteracts that of the substrate. The remaining temperature instability can then be further compensated by a method of digital compensation as known in the previous art.
¦ Operating power is supplied to the ASH unit by a rechargeable battery 20 l 36, which is initially charged and recharged by appropriate solar cells 38, an whose charge condition is monitored by a charge sensor 40. As will be under-stood, the MESH unit of FIGURE 1 drops in and out of operation, depending llpO~I
whether the available battery power does, or does not, exceed the threshold of the charge sensor 40. Exceeding such threshold will be seen to result in the activation of the ASH unit, and in the initialization of all its functions, (As will also be understood, the clock lo activates scheduled frequency and/or code cages for the unit, provided the power be continuously supplied for such purpose All ASH unit clocks are to be synchronized prior to the deploy-mint in the communications field, in any appropriate manner.) prefer red eDoodi~.ent of the MESS omit is shown in FIGURE 2, Ike uric If If I
As is well known and understood, a wide variety of problems come into play in operating a radio-con~Lnicatic~s systent in a hostile environment. For example, r,tessage traffic flow from user to user and from node to node or front relay station to relay station is usually controlled by centralized units which l are of far higher corrtplexity, value, weight and bulk than the relay or user stay 1 lion. In digital communications systems this centralized unit frequently is acornputer Lucia operates together with a large collection of peripheral equipment This means that the whole system is hierarchically organized such that the open atonal availability of the whole system depends on the availability of the highest member in the hierarchy, the central control unit. ~orneone who is in-terested in deactivating the system only has to concentrate his efforts on de-activating the central control unit . Isles task is simplified by the fact that these units are much easier to detect and easier to destroy than the lower and more expendable members of tile hierarchy.
l Also contributing to problems in their usage, such conrnunications soys-1 terms most often operate at UHF frequencies, where tall antenna structures arereouired for line-of-sight transntissions -- especially in wooded areas and in localities where other obstructions such as buildings predominate. ugh antenna structures increase system vulnerability to detection, electrical interference I and physical destruction.
J
lath the tecttnolo~y frequently e cloyed in their construction, no will-the manners of their implementation, such communications systems offer further disadvantages in that their component parts have to be repaired, replaced and maintained -- because of their expensive costs and non-disposability. This leads to additional problems by requiring a dedicated supply, storage and no-pair organization whose own limits in availability contribute to limits in soys-them survivability.
In order to make a communications system less detectable one has to oh-sure its appearance. While nothing can be done to reduce a given physical size, one can try to hide system units, e.g., in natural or man-made cover and one can give its electrical emissions a noise-like appearance, e.g., by spread-in its electrical emissions over a large frequency range by so-called spread-spectrum methods. However, physical hiding interferes with loneliest open-anion and spectrum spreading increases the cost, complexity and, hence, the physical bulk of the system units.
In order to make communications and communications systems less vulner-able one usually tries to supply a sufficient number of back-up copies of soys-them units and messages, i.e., one increases redundancy. This again can only be bought at higher costs and complexity or one has to accept a decrease in system performance by only partly utilizing the system, i.e., by slowing down or reducing the message traffic.
Other disadvantages of such prior art communications systems will also be readily recognized: a) The high cost involved because of limited product lion runs; b) The continuing use of increasingly obsolete designs so as not to incur the additional costs of new developments; c) The high degree of train-in required in the utilization of the communication equipments; d) The Defoe-gully in transporting about, because of weight, size and bull.
s will become clear hereinafter, the electronic communications and con-trot system of the invention comprises a fully distributed, disposable, self-organizing, self-powered communications system. when deployed, it will paraffin its junctions by simultaneously maximizing the survival of the system under all foreseeable threats during the time interval in which the system is needed. As will be seen, the communications system operation entails the randomly seeding of an area with system units.
ore specifically, as will become clear from the following description, these system units are each small, disposable transceivers, which are self-powered, and which include a defined amount of built-in digital processing llcapability. Preferably contained on a monolithic semiconductor chip utilizing livery low power technology, these transceiver units would be powered by a suitable energy storage device such as a capacitor or a plastic-encased thick film or gel ¦
battery which could be made rec~rgeable by a battery of solar cells.
in a preferred embodiment, the entire transceiver unit is attached to a¦
piece of thin plastic material, which can then be deployed as easily as anti radar "chaff", e.g., by airplane (drone), rocket, balloon or barreled weapon. The plastic film is to be shaped in such a way that it will become entangled in obstacles such as tree foliage and/or other ground cover. The plastic film is additionally to serve as the base material for an appropriate I printed antenna structure -- with the carrier frequency being such as to allow llline-of-si8ht operation, even in wooded areas, and preferably outside the established capabilities of a potential jammed, or at least in a range where an attempted jamming would require a large investment in equipment usage and power dedication. A suitable carrier frequency, according to the invention, would be at, or above, 12 I and in the interest of power conservation a pulsed carries is to be used, with modulation being combined with suitable spread-spectrum schemes if needed.
In accordance with a preferred form of the invention, system operation ., , 77~
is initiated by random distribution of system elements over an area which bridges the distance between two, or more, operating tenmm at stations. Such terminal stations may be of the type including commutlicatiatls stateless, sensor elements, remotely activated or operating electronic systems, or remotely anti-voted or operated automata or robot systems, with the system elements being de-plowable either before, or after, the terminal stations have been established.
As will be seen, such system elements may even "wait" in a dormant state in some potentially hostile territory, until being called into action.
The system is a homolog~te by virtue of the fact that all system units are of exactly similar construction with similar operational capabilities.
There is no hierarchical organization whatsoever s will be readily understood by those skilled in the art, the dispose able transceiver system elements can be recruited into the cumm~nications net-Turk by call signals issued by the terminal stations, requesting access to the network. Those system elements nearest to a terminal station would then no-spend to the call, and relay it to the system elements nearest to them, and so on. When a call finally reaches its destination, all disposable transceiver system elements which have contributed to the linlcing of the two stations to-getter Toledo then became "members" of a particular data path; all other disk potable transceiver system elements which have not yet achieved such a linking would "drop out", and return to the standby wait for reception of the recruit-in call mode. In furtherance of the system network, different operating and control modes -- as well as terminal stations and system element identifiers -- will be seen to be represented by suitable codes established in accordance with an operations protocol.
The way in which system elements contact each other can be thought of as being similar to the way in which data-processing elements in living systems nerve cells, contact each other through their synapses.
These and other features of the present inverttion will be more clearly , 1,~.~,3'~.t~
understood from a consideration of the following description, taken in connect lion with the accompanying drawings in itch:
FIGURE 1 is a functional block diagram of the electronic communications and control system transceiver element according to the invention;
FIGURE 2 illustrates a suitable packaging for tile transceiver system element as will permit easy deployment by airplane, rocket, balloon, barreled weapon or other suitable deployment c~lveyance;
FIGURE 3 is a block diagram, in implied form, of a terminal station as might be employed in the system operation;
¦ FIGURE 4 is a block diagram illustrating the addition of further terming Sal station equipment for employing the disposable transceiver system elements in a multi-channel operation, for example, and in a communications nitric to be compatible with other, different communications formats and systems; and FIGURES 5-10 are flow diagrams useful in an understanding of the present invention.
As the communications and control system of the invention can be viewed as a multiple electronically synapsing homology the system description and come pennants will, for the sake of siinplicity, be hereinafter referred to by the acronym MESH. Thus, referring to the block diagram of the MUSH unit of FIGURE
1, reference numeral 10 identifies the central processing unit, which, through its inpu~/output circuit 12 controls all unit functions. The programs for all its modes and, in the case of connected terminals all interfacing characters-tics, are shown to be stored in a read-only memory 14. Temporary storage for the processing functions and message buffering is available in a random access n or 16 and in a stack of registers (not shown). All timing functions -- as well as frequency synthesis -- are controlled by a master clock 18.
In the receiving mode, the antenna 20, through the antenna switch 22, is connected to the receiver 24, which derives its local oscillator frequency prom the frequency synthesizer 26. The received signal is demodulated in the 1~771~
demodulator 28, from where it is routed to the central processing unit 10 through the input/output circuit 12. In the transmitting mode, the transmitter switch 30, under program control from the central processing unit lo (through the input/output circuit 12), switches on the modulator 32 and the transmitter 34, and connects the antenna 20 to the transmitter output by means of the an-henna switch 22. The processed base band signal from the central processing unit lo is applied, also, to the modulator 32 by means of the input-output circuit 12, with the modulator 32 then supplying a modulated intermediate ire-quench to the transmitter 34 whose carrier frequency is supplied, or ccntrolledJ
lo by the frequency synthesizer 26. A temperature drift, affecting clock frequent cry, would thl~sly have the same direction of deviation in the transmitter 34 as well as in the local oscillator, and, hence, the receiver tuning frequencies of all ASH units deployed in the same envirc~ment would have the same direct tonal deviation It is, of course, possible to improve the basic clock stay ability by bonding the substrate of the integrated circuit to a material whose thermal expansion counteracts that of the substrate. The remaining temperature instability can then be further compensated by a method of digital compensation as known in the previous art.
¦ Operating power is supplied to the ASH unit by a rechargeable battery 20 l 36, which is initially charged and recharged by appropriate solar cells 38, an whose charge condition is monitored by a charge sensor 40. As will be under-stood, the MESH unit of FIGURE 1 drops in and out of operation, depending llpO~I
whether the available battery power does, or does not, exceed the threshold of the charge sensor 40. Exceeding such threshold will be seen to result in the activation of the ASH unit, and in the initialization of all its functions, (As will also be understood, the clock lo activates scheduled frequency and/or code cages for the unit, provided the power be continuously supplied for such purpose All ASH unit clocks are to be synchronized prior to the deploy-mint in the communications field, in any appropriate manner.) prefer red eDoodi~.ent of the MESS omit is shown in FIGURE 2, Ike uric If If I
2;~7~80 is shown in deployed form. The body 54 of the unit would be one piece of pies tic material which is prestressed in such a Jay that the depicted shape is automatically assumed as soon as the Unlit is freed from the deployment package In the packaged state the unit body 54 would be opened flat and lie in the same plane as the legs 50, tightly packed in a stack with other MESH units.
The legs 50 are distributed in such a way that the unit's landing on three legs is always assured. The legs 50 will also serve as substrates for the solar cells and reasonably omnidirectional antenna conductors. A sensing air-cult in the transmitter can be made to detect which of the legs are closest to a solid surface, e.g., by a rough measurement of the reflected wave as crown from previous art. An into m at switching circuit would then make the antenna structures on these legs the ground plane and the antenna conductors on the rev mining legs the radiators. The leg tips 52 would be covered by an allusive ¦ which would be activated upon contact with air and kept inactive by a suitable gas in the deployment container. The adhesive would be iced with, or duster-butted on top of, a similarly air-activated foaming agent which would keep the device afloat should it land on water. If the foaming reaction is exothermic, the adhesive could as well be of a heat-activated variety. Lyle adhesive will l make the first leg that contacts a surface briefly or permanently adhere to ¦ the surface whereupon two more legs will contact and adhere to the surface. If the adhesive strength is insufficient, the process will repeat until terminated by curing of the adhesive. Thus, if a MESS unit hits a vertical surface, e.g., of a building, it will actually "walk" down the wall of the building until it has found a stable position where it will stick out from the Hall, ready to act as a radio-relay station. In wooded areas some ASH units will adhere to loll-age in tree tops, other will fall to the ground or establish themselves scone-where in-between. ASH units that land on other objects, such as vehicles, could be used as ving-target indicators. ale inside and/or outside of the body I would preferably be used to hold the other components and circuit eye-newts of F JOE 1.
I
1, if 1;~377~
he MESH unit would be a mass-produced device which by virtue of its production in extremely large numbers would always justify its redesign as to reflect the latest state of the art. presently, it could be expected that the arrangements of FIGURES 1 and 2 would use ribbon-grown or amorphous technology for the solar cells 38. All the elements of the SO unit are printed or rolled cmto, or produced simultaneously with, the carrier as shown in FIG UP 2.
The rechargeable battery 35 utilizes a weight-and-volume efficient process, preferably employing a Lithium couple. All the remaining linear and digital circuitry is integrated on a single semiccmductor chip of extremely-low-po~er, very-high-speed, and very-high-density technology, probably utilizing cycle rnentary-metal-oxide-semiconductor tec~mology on one of the III-V or II-IV semi-conducting compounds, such as Gallium Arsenide. Interconnections will utilize leafless chip-carrier and tape-autc~ted-bonding techniques, kowtowing all con-ventional encapsulation. If the unit elements of FIGURE 1 are not embedded in the body 54, a thin plastic covering will contain the battery materials and protect the electronics, thereby providing equal life expectancies for all the components of the ASH unit under given environmental cloddishness. the whole MESH unit will weigh at most a few grams and iII deployed foreign only be approxl-l mutely between 2 and 3 centimeters long.
20 ¦ loath the arrangement as thus described, it will be appreciated that the EYE system is based on small, cheap, extremely light weight system elements, which can be deployed extremely simply and in very large numbers. because of this, field maintenance is no longer really necessary, except to store the SUE units and to monitor their shelf life by expiration date only. Because the logistics is then similar to that of the storage of soap, ~Dn~ulition or other disposable items, the corrrnunications system of the invention will be seen to obviate the need for, and updating of, extensive field documentation, main-tenancy and test facilities, and the spew training of user and maintenance personnel. it the same time, the introduction and updating of technical dock-mutation testing and personnel training will be seen to be required only at 1 :lZ3778~
the manufacturing facility. The most expensive operation in conventional electronics manufacturing, that of testing, will be reduced to the testing of random samples during any production run. As such, the user only needs to know the expected value of the yield of operational devices avid its distributiorl in any given manufacture.
The MESS user and interfacing units shown in FIGURES 3 and 4 include essentially similar elements as shown in FIGURE however, the hardware illustrated in these two drawings differ in the requirement of exhibiting a high Reliability characteristic -- such that for example, the chip containing the illuminates of FIGURE 1, in the constructions of FIGURES 3 and 4, would be conventionally encapsulated and fully tested. Additional testing expenses associated with these constructions, however, can still be largely eliminated to¦
the extent that the MESH units employed are available from the random sampling testings carried out in the original MESH production. reference numeral 60.) ! According to user requirements in the communications mode of operation the input/output circuit of the individual MESH unit 60 might be required to interface with external equipment and/or circuitry -- such as analog-to-digital and digital-to-analog converters, crypt devices, sensors and analyzers of biological parameters (for user authentication, for example), special-purpose sensors, processors, actuators, transmitters, interfaces to other systems, etc. !
As an example (and referring to FIGURE 3), the chip can be interfaced with user peripherals such as an authentication unit 62, analog/digital conversion circuitry 64 for voice in/output, data terminal equipment 66 such as a keyboard i I
, . , . .
g ! ¦
lZ3~7~7~
I to or wit trout do splay or a graphics digitizing pad, and a it me do splay 68. (As indicated, the unit is also powered with its own high reliability battery 70.) If user requirements exceeding the normal MISS capability, but not exceeding the MESH specification, are to be accommodated, additional external equipment can beadded, as shown in FIGURE 4 -- such as a multiplexer-demultiplexer I for multi-channel operation, crypt equipment 74 to provide for data security, a coder/decoder 76 to improve error rate and, if needed, an interface 78 to make non-MESH hardware compatible with the ASH input/output circuit.
In operation, and referring to thy flow diagrams of PHARISEE 5-10 --, when sufficient battery charge is sensed by the charge sensor 40 of FIGURE 1, appropriate power is supplied to the processing circuitry there shown and the functions are initialized, switching "on" the central processing unit 10, its peripherals and the receiver indicated, also actuating the system monitor and clearing the various counters and buffers. The central processing Kit then checks the receiver output for incoming Calls (KIWI?). If a call is received !
(500) the central processing unit then checks whether the call came from a validsource (OLD SAC?), i.e., whether the authentication code in the header of the unit is correct. If that is not the case, the central processing slit then I, returns to label 400, to await an authentic incoming code signal. Upon reception 20 11 of a valid incoming Cole the central processing unit checks for mode ,1 1 ,, .
If , , ', !
.
- 1 o -If ~.Z3~
information in the header (M), and in the event of rode branches, couples it to label 3000 (see FIGURE 9). The some sequence occurs if the next check (carried out in the unit BUY MTY?)shows that there are untransmitted message units or packets (P) in the R3-mode buffer, indicating that the buffer is not empty.
However, if the buffer is indeed empty, the next question in the flow diagram is whether the message units have been handled before and its header (H) is therefore stored in memory I. If is found in I (label 700) and the incoming H does not have an acknowledge request code (NO 2) in its network function field, the program then branches back to the label 400 to check again -- otherwise, it will check if the old H in I already contained the acknowledge request OF 2) function. If an H is found in M, and an acknowledge request NO 2) is located, a branch to label 400 occurs (NO 2 being able to override "H in I only- once). If no 2 was in the stored H, the present H containing NO 2 will override the stored H (H -if M), and the program then continues at label 1000 (FIGURE 6). With a negative "I in M" test (label 900 in EI~JRF. 5), a further test (H in V) reveals whether the message header (H) is held in a temporary register (V). In the negative case, the incoming is written into V, and a counter is set to a maximum allowed for incoming Koalas (SO CUR).
This leads to label 950, which is followed by decrementing the COWAN in counter once, and a return to label 400.
If, on the other hand, H was already in the register V, the OAKEN count or is tested (KIWI CUR = 0?). If it is 0, a branch to label 1000 occurs, other wise label 950 is reached. If the CQI-test was negative (label 600), a test would have been made whether the message header (H) was held in the temporary register V (H in V?). If the test turned out negative, branching back to 400 occurs. In the affirmative case, H was received before, and an additional test determines whether too much time (MOE?) elapsed since the last KIWI, then label 650 is reached, but if not, return to label 400 occurs.
At label 650, it still nut be tested whether the mode required in the lZ3`778 header (H), as held in the register (V), is the wide-path random walk (R2?~.
In the affirmative case, label 800 is reached after storing the V-content in an appropriate location in memory My=); in the negative case, label 800 is reached immediately. After that, V is cleared (CUR V), and the program returns to label 400.
Lo Flume 6, at 1000, the present reading of the real-time clock (RTC) is written into the appropriate H-field in the V-register. Then the V-cantent with an acknowledge CQ-NF3 functional code inserted is transmitted (CQ-acknowl-edgement). The next decision point is reached (in practice after a suitable time delay), when a test is made whether H, as transmitted between labels 1000 and 1100, together with P and a send-P function NO 5 have been received (P/NF 5 LO?). If this is not the case, the program tests for a request for random time delay CON 4 LO?). East of such a request causes a random wait beginning at the present RTC-time (Eureka + DEL), followed by a return to label 1000. If no NF-4 "delay request" was received test is made whether the present PUG
time minus the time at which OF 3 was sent exceeds a ~ximum (RTC-TV IVY.
If this is affirmative, it is assumed that the service-requesting SUE
unit selected another MISS unit to handle its message packet and the program returns to 800; otherwise, the V/N~F 3 - transmission, etc. is repeated by no-turrlin~ to label 1100.
If the (P/NF 5 IN?) test result was affirmative, i.e., that the message packet (P) is then in this 'ASH units P-buffer, label 1200 was reached Lowry the hop count (I) in the header (H) is incremented by 1 (I = I + 1). If the new I then equals the m~cu~im (I = MY.?) specified for this Misfiled, fur-then P-travel will be prevented. As will be understood, it is only necessary to test whether D2-service was requested (Do?) -- where user units, i.e., data terminals (D) have assigned, e.g., alpha-numerical identifiers which can be changed as required, and which are needed to identify source (Do) and destine-lien (Do) of a message message omit or packet UP) in the n~ssage header (H).
he pr~gr~n coos into the batcery-che rut m e (2600) if this was not the gas i 1~3'7~
-- otherwise into (1250) --, where it will notify the previous MISS unit of a lost packet (P) by transmitting V/NF 8 first, and then run the battery check According to the program, a battery check is always performed at the end of a program loop, if that program segment contained steps involving high battery drain, i.e., operation of the transmitter.
IJithout an affirmative DMAX-test result (1300), it is still necessary to test for D2-service. If no (Do) message destination is requested, Precept lion can then be acknowledged TV 6), otherwise this is postponed. The next steps store the V-content in M, inserting the NO 1 "sending CQ function" into the register (V)(1400) and setting the transmit-CQ counter (SEC CUT prior to reaching label 1500.
At label 1500 (FIGURE 7), the ASH unit begins its attempt to transfer the packet (P) to the next MISS unit (designated Us, with its V-register design noted as V2). The first MISS unit (U) transmit a Cole (VNF 1) once, decree vents the Kowtow counter DO OKAY CUR), waits pharaoh a signal-round-trip time (not shown) and then tests for reception of a CQ-ackncwledg~ment (V2/NF 3 r1?) which could come in after the first Call provided Us was identical with I the addressee (label inn FIGURE 7). Usually, this will not be the case all the program will branch to label 1600 (FIGVR~ 8). If, however, label 2000 was reached, the V2 (the if with Use RTC-time) is stored in V and toe transmit-P counter is set (SUP CUR). At label 2100, P with the V-ccntent and NO 5 "send P" function is transmitted (P + V/~JF 5) and the P-out decrement Ed once (DEW PO CUR) to reach label 2200 where a test is made for P-acknowledge~ent (V2/NF 6 I If this is affirmative (label 2500), I must be checked again.
If it was requested, P had not been acknowledged between labels 1300 and 1400 and must be acknowledged now (V/NF 6), followed by a WriteNow to the battery-check routine 2600.
A negative V2/MF 6-test result (label 2300), an the other hand, require a test whether repeat of P-transmission was required by Us (V2/NF 7 IN?), in-dilative of a repeat of the packet (P) requested. The affirmative case simply Aye results in a return to label 2100, but in the negative case (lube]. 2400), the Pout counter is checked (PO CUR = 0?). If it is not zero yet, then return to label 2100 occurs. If the noisomely permissible number of P-transmissions has been exhausted, then the program will either return to the battery check routine 2600 or, in the D2-case, notify the previous ASH unit of a lost packet (P) (label 1220, FIGURE 6).
The case of the negative V2/~ 3 - test result (label 1600) is shown in FIGURE 8. A test is made whether a V2, garbled by another carrier, has been received ((V2)/CS run?). This would require a delay request (NO 4) in the register TV an a return to label 1400 (FIGURE 6). If nothing has come in (label Thea O?O-counter is checked -- and if it has not yet Len down to zero, return to label 1500 is indicated. If it is zero (label 1300), it is necessary to test for the NO 2 "acknowledge request", i.e., whether an ac~lowl-edge-request series has been transmitted previously. If this is the case, the program returns to label 1220; and, if not, then the NO 2-request is inserted into the register (V), the Kowtow counter is set to a n~ber adequate for 2 -transmissions, and the program returns to label 1400.
An R3 service request or unfinished R3 business diverts the progrc~n to label 3000 (FIGURE 5), continuing it from there, as shown in FIGURE 9, where first the memory is searched to determine whether it contains .'~ of the in-coming call (!~ DUN I?). If this is the case, the program returns to label 400 of FIGURE 5. A negative test result (label 3100, however) requires a check whether the padcet (P) is held in the P-buffer. If P is fund in the buffer, it was not errOrfree and the incoming copy of P is used to correct errors in the previous copy. If the message packet (P) was not yet in the buffer (3200) on the other hand, and there is still space in the buffer, P is read into the buffer (3300). If, however, the buffer were full (BUY FUR?), then the inks-in message packet (P) cannot be handled at this time, c1nd the buffer address of the P that has been in the buffer the longest is pointed at by a transmit-flag (XFL) register AL TAX) ion idiot ire stussicn, by label 3600 ~23''77~) , I .
If label 3300 was reached, and there is a message packet (P) in the Buffer for which the error detection is zero (ED = 0?), the "XFL" flag is set topoint at that packet (P) (3400), followed by the label 3600.
If all P in the buffer contain at least one error (at unit 3500), a test is then made according to the program, whether one of the P has reached themaximally pennissible storage time (TAX ?). In the affirmative case, the header(H) of that packet (P) is then marked with an error flag (ELF - H) and "XFL" flag¦
set to point to its address, followed by the label 3600. A negative Attest Returns the program to the point 400 of FIGURE 5.
I The Retransmission sequence begins at point 3600 in Flyer 10, with a single transmission of the header (H) us pointed to by the "XFL" flag. After that, the transmit counter (XMr CUR) is set (SEX CUR) and the buffer content indicated by "XFL" is transmitted US (XFL)). Then, the transmit counter is checked -- and, if it is zero, H is stored in memory (~) and the progr~n continues to label 2600. If the counter is not yet zero, it is decrement Ed once (DEW CUR) and the transmission repeats itself again.
As will thus be seen, and as will be understood by those skilled in the art, the MESH system elements thus perform the following functions:
a. In the recruiting mode, the elements receive incoming signals and validate them according to their identifying and control code (the latter indicating a recruiting signal). Depending Oil the quality of the cleanly (e.g.noise, attenuation, multi-path distortion, etc.) between the signal source and the receiving unit, a certain number of calls would be required before enough error-free signals would match the count in the preset counter of the unit.
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rho system element wall then issue an acknowledgement to the calling station, thereby silencing it, and will start transmitting call signals of its own.
b. In the communicating mode, on the other hand, the system element will relay only messages from terminal stations which were the originators of the original calling chain. However, it will accept and acknowledge recruiting calls from the other terminal stations involved, provided their call is addressed to one of the terminal stations of the Issue unit in question. The system element will thus store addresses of all terminal stations l with which it communicates.
if On the other hand, the So unit operates upon the receipt of a proper command, and in response, will switch its code generator to any other code and/or change its preset counter number as the case may be. In such instance, if the system element in the communicating mode then attempts to relay a message to the next system element in the network, and that unit does not acknowledge the address, the transmitting system element will notify the message originator of a break in the chain, and then switch to its recruiting mode.
Message routing in the ESSAY system is thus determined by the operating mode of its individual unit. Such mode can be selected from a menu, according id tithe invention, in firmware by the appropriate code in the header (H). Two basic 20 Al code schemes according to the invention can be identified as the "random walk"
(Al) and the broadcast mode (K3~ -- but can be modified further by a "wide-path"
random walk (R2) and a form of end-to-end control for Al and R2 by an automatic message acknowledgement according to message destination and source llidentification (DO, Do, respectively), resulting in routing schemes Al, Do and ;~R2, DO, for example.
Al The user's data terminal equipment, D, allows for the selection of one ., I .
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If if _ 1~3' i''7~0 ¦ operating de from a series available to that particular user, thereby giving¦ a greater choice of operating modes to a higher-priority user than to a lower-¦ priority user. The terminal equipment (D) will then place an operating code, ¦ OPT, into the designated field which identifies the routing scheme correspond-in to the operating mode under which the message (P) was issued. Such code ¦ can be appended by a sufficient number of bits to identify various network management functions (NO) such as pa) Send CQ; (b) Acknowledge Pickiest; (c) Acknowledge CQ; (d) Delay Request; (e) Send P; (f) Acknowledge P; (g) Pickiest l Repeat of P; and oh) Loss-of-P Notification in D2-Mode.
¦ In this manner, the Al and R2 modes support P-travel within a ASHfield from one originating data terminal (D), i.e., Do, to one destination (Do) via a random walk that links Do to a succession of MESH units terminating in Do. P-transfer is initiated by Do by means of repetitive Koalas which con-sit of H with the appropriate operating code (OPT). Any neighboring IFS
unit that is not busy with other tasks will then receive the CQ and compare incoming H-fields with its own stored validation and authentication codes.
The process then repeats until a MESH unit achieves a predetermined number of matches, which could either be part of the header information or stored in firmware. The number of required matches serves as a threshold for ~4-ackn~l-edgement from the ASH unit. Since that unit which receives the Calls with the least interference, attenuation and delay will acknowledge them first, the message will be made to travel over the best available channel, from the oft-jointing unit (Do) to its so-linked neighbor. Acknowledgement then consists simply in a retransmission of the header by that neighboring unit, along with the network function indicating ackncwledp,ement plus the neighboring unit localtime of retransmission. Reception of an acknowledgement thus causes the originating ASH unit to terminate its Killing sequence, King it impost-isle for most other neighboring MUSH units to reach their thresholds for in-coming Koalas If, however, more than one Masonite has reached the C?
threshold, they will then compete for the same message packet by acknowledgit~
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the CQ.
But, in accordance with the present invention, there exists three lea-lures in the N and R2 modes to help break such a contention case between neighboring So units -- (l) Carrier Sense Multiple Access (COMA); (2) Local-Time Tag; and (3) Random Acknowledgement Delay.
KIWI is used in the MESH units of the invention, and operate in such a way that a transmitter at an originating location or at a neighboring location can be switched on only after the receiver of that particular unit was unable to detect any other carrier on the air. Depending upon propagation delays be-tweet the originating unit and contending SUE units, SHIM may be sufficient to break acknowledgement contention. however, if neither of the contenders did detect the other's carrier in the time required to block their own trays-mission, they may acknowledge about the same time. Since each acknowledgment will be supplemented by the local time of the acknowledging SHEA unit, and these times are highly unlikely to be the same, the received acknowledgements can be ascribed to particular MESH units by the originating system element, providing the original unit's processing time is less than the difference in arrival times between acknowledgements. In this case, the message would be addressed to that MESH unit whose acknowledgement arrived first, i.e., the message would be transmitted with the header supplemented by the local time of the addressee. Any contending So unit would then refuse to handle the mess-age packet by simply ignoring it.
If acknowledgements arrive at the originating unit so close within each other that there is not enough processing time to read and separate the local times, the acknowledgements will then tend to destroy each other. In this case, the originating unit will send a repeat CQ according to the invention, this time with the management function NO indicating a random delay request. Con-tending message units receiving this CQ will then wait a rundown time interval before attempting acknowledgement. The entire process then repeats until con-tenders are separated either by COMA, or by local-time differentiation. After ; -18-I 3 7 To that, the originating unit will send its message packet to the first ISSUE unit in time, which then can be assigned a designation (Us), the originating unit having the designation (Do).
(In the R2 mode, all MESH units use) which received a copy of the I
but did not become Us would store I and from then on, Rufus handling a P be-longing to the header (~) .) After Do has transmitted its message packet to Us, it has completed its task, and Us would then attempt to dispose of that message packet by repeating all of the previously described Dl-functions, i.e., the message packet (P) would be handed to another Ho unit (U) become Us. At that time, Us would have stored H which prevents it from reaccepting that particular packet (P).
The packet (P) tlould then travel from Us to Us, and so on, ctlong a path which resembles a "random walk". As will be appreciated, the loop cannot come back on itself, because no previous handler of the message packet (P) will handle it again, with one exception -- which may arise when P travels towards the edge of the SHEA field in such a way that it wiped out all return possibilities behind it: in that case, the Koalas of the ?IEShT unit nearest to the field edge will not elicit an acknowledgement, and only then will the MOE unit place an acknowledge request into the NO field and reissue Koalas Such "acknowl-edge requests" will override the rehandling refusal in any previous Ml~:S~I unit, with the packet (P) then traveling from Us to fin I whereupon Us 1 removes the "acknowledge request" and tries to pass on the packet (P) in the usual way.
If this fails, an attempt will be made to reinstate the acknor.Tledge request, etc. According to the construction of the units in the block diagram strikeout any I unit that has handled a packet twice will be prevented from handling it a third lime under any circumstances, so that the packet (P) us forced away from the edge of the flesh field.
wherever a Cole is received by a data terminal for which it is desk lined (Do), then that terminal will acknowledge the I irlmediately in order to l terminate the message packet -travel.) SUE
According to the invention, the message header (~) also has a field for the accumulative hop count. This is a number which is incremented every time the message packet (P) is received by a MY unit (U). Another field in the header (H) contains a number which determines a maximal hop count. whenever the accumulative equals the maximal hop count, no further I will be issued by the receiving hush unit, so as to assure that the packet which does not reach the desired destination after a number of trials will be deemed unreasonable for the ¦
size of the MESH field, and will be abandoned. If the packet priority warrants Kit, a Deporting mode can be included to notify the originating unit of the lost packet, which could then be retransmitted, and in a R3-mode.
Such R3-mode is a broadcast one in which the message packet exhausts all the resources of the ASH field once. In this mode, it is virtually impossible for an existing intended destination not to be reached by the packet, and is very useful for reaching classes of destinations, i.e., all binary digits within the field so as to sub-divide the class. In this mode, the originating unit only issues a single Call to initiate all neighborir~, unoccupied MUSH
units to the R3-mode. This is followed by repeated transmissions of 11-P
sequences, which are to be accepted by each Howe unit in the mud, putting it lint a buffer. Each unit would continue accepting the packet (P) until all terrors are corrected, or no further packets (P's) are received. it that time, the MESH unit would store the header to bar rehandling of the packet (P), and proceed as Do, the originating station, did before. In this fashion, the message , packet will travel as a single expanding ring around the originating station, an will even travel backwards if a MY unit has been missed, either due to an obstacle or because of temporary non-availability. Such feature makes it possible, therefore, for two or more, P-rings to penetrate without annihilating teach other. Only at the boundaries of the ESSAY field, would such P-ring be destroyed As thus described, certain advantages will be definitely seen to exist I Jo if l ~L'Z3~77~
- I utilizing the cwn~unicaticns system of the present invention. First, the soys-tern will be seen to be a totally probabilistic one in every respect, consisting of a set of system elements of which only a subset, c~eterrnined by the product lion yield in that particular set, would be operational at any given time. A
still smaller subset, determined by battery-charge conditions and message-traffic loading, would be taking part in system functions. ~11 system elements temporarily or permanently not engaged in system activities, would still act as decoys to foil search and collect operations.
Secondly, direction finding, or tracing, of cc~nunication paths will be seen virtually impossible due to the random and continually changing disturb-lion of active system elements. terminal stations will be seen not to have any specific signature which could allow one of them to be distinguished from the system elements being used.
Also, the line-of-sight operation introduces no detrimental effect since all line-of-sight obstacles simply act as supports for the system eye-mints, thereby proving a disadvantage to a potential jammed. ~ltipath effects will be seen to result in negligible multi path spread, as well, due to the short average distance between system elements in operation. In because the transmitter power of active system elen~nts is so low as to be nearly India-tinguishable from a widely dispersed low-power-random-noise source, convention-at systems that operate in the same geographical area will experience only a slight raise in background noise which is not likely to interfere with their normal function. Conversely, a strong conventional emitter within the ASH
field, operating in the same frequency band, would incapacitate only a relative lye small number of SUE units. message traffic jollied simply route itself crane the disturbance.
s will be apparent, the ASH construction is eminently suitable for communications and control in geological and jungle exploration, mining opera-lions, explosives removal, nuclear and toxic removal and clean-up operations, fir ghting, etc. It it a desirable system for disaster preparedness em d for establishing c~nmunications during an emergency and after a disaster has occurred that wiped out all conventional means of communications. Necessary terminal stations, not larger than a wrist watch, can easily be airdropped together with the ISSUE units, e.g., by dangling them from small marker pane-chutes or long, brightly colored ribbons on which could be printed the open-a tying instructions. SUE terminals could be dispensed as part of survival packages for sea and air travel and transport crews, forest and park rangers, etc. ILSH is also particularly suitable for all purposes where the user must not be encumbered by clumsy equipment or restricted in his movements by line-lo of-sight requirements. It is an ideal system for the communication Thea, and control of, autonomous or semiautonomous robots.
Intelligence and reconnaissance operations in hostile territory could similarly benefit according to the system of the invention -- as an operator in enemy territory is only called upon to use a transmitter with extremely low output power, just sufficient to enter the nearest neigliboring So unit.
Interception of such ITCH communication, however, would give no clue as to the location of the terminal station, as previously indicated. And, to prevent "spoofing" -- i.e. an unauthorized entry into the system --, the terminal stay lions can be linked to vital functions of their carriers in use in the commune cations network -- such as to a biological-electrical signature, in the nay lure of electrocardiogram, electroencephalogram, or other available identify-in indicia, so as to grant access to the system only to authorized users.
Cryptosecurity can be introduced rather easily either by storing enough crypt tokens in a read-only memory of each unit, where, e.g., the message n~ber could determine the key selection, or by conventional means eta m at to the ASH system. Code brealcing attempts would take longer than the life time of a particular SUE field.
initial charging of the batteries could be accomplished inductively through the deployment container by replacing the connection to the solar battery with a connection to an inductive antenna loop via a rectifier diode.
.1 I 1~3'7~U
Upon deployment this connection could be broken, erg., by an air-triggered exothermic chemical reaction which would also fuse the battery terminals to the solar battery. This same action could be used to initialize the system units and synchronize their clocks.
While there has been described what is considered to be a preferred em-bodiment of the present invention, it will be readily appreciated by those skilled in the art that modifications may be made without departing from the scope of the teachings herein. For at least such reason, therefore, resort should be had to the claims appended hereto for a correct understanding of the 'I in
The legs 50 are distributed in such a way that the unit's landing on three legs is always assured. The legs 50 will also serve as substrates for the solar cells and reasonably omnidirectional antenna conductors. A sensing air-cult in the transmitter can be made to detect which of the legs are closest to a solid surface, e.g., by a rough measurement of the reflected wave as crown from previous art. An into m at switching circuit would then make the antenna structures on these legs the ground plane and the antenna conductors on the rev mining legs the radiators. The leg tips 52 would be covered by an allusive ¦ which would be activated upon contact with air and kept inactive by a suitable gas in the deployment container. The adhesive would be iced with, or duster-butted on top of, a similarly air-activated foaming agent which would keep the device afloat should it land on water. If the foaming reaction is exothermic, the adhesive could as well be of a heat-activated variety. Lyle adhesive will l make the first leg that contacts a surface briefly or permanently adhere to ¦ the surface whereupon two more legs will contact and adhere to the surface. If the adhesive strength is insufficient, the process will repeat until terminated by curing of the adhesive. Thus, if a MESS unit hits a vertical surface, e.g., of a building, it will actually "walk" down the wall of the building until it has found a stable position where it will stick out from the Hall, ready to act as a radio-relay station. In wooded areas some ASH units will adhere to loll-age in tree tops, other will fall to the ground or establish themselves scone-where in-between. ASH units that land on other objects, such as vehicles, could be used as ving-target indicators. ale inside and/or outside of the body I would preferably be used to hold the other components and circuit eye-newts of F JOE 1.
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he MESH unit would be a mass-produced device which by virtue of its production in extremely large numbers would always justify its redesign as to reflect the latest state of the art. presently, it could be expected that the arrangements of FIGURES 1 and 2 would use ribbon-grown or amorphous technology for the solar cells 38. All the elements of the SO unit are printed or rolled cmto, or produced simultaneously with, the carrier as shown in FIG UP 2.
The rechargeable battery 35 utilizes a weight-and-volume efficient process, preferably employing a Lithium couple. All the remaining linear and digital circuitry is integrated on a single semiccmductor chip of extremely-low-po~er, very-high-speed, and very-high-density technology, probably utilizing cycle rnentary-metal-oxide-semiconductor tec~mology on one of the III-V or II-IV semi-conducting compounds, such as Gallium Arsenide. Interconnections will utilize leafless chip-carrier and tape-autc~ted-bonding techniques, kowtowing all con-ventional encapsulation. If the unit elements of FIGURE 1 are not embedded in the body 54, a thin plastic covering will contain the battery materials and protect the electronics, thereby providing equal life expectancies for all the components of the ASH unit under given environmental cloddishness. the whole MESH unit will weigh at most a few grams and iII deployed foreign only be approxl-l mutely between 2 and 3 centimeters long.
20 ¦ loath the arrangement as thus described, it will be appreciated that the EYE system is based on small, cheap, extremely light weight system elements, which can be deployed extremely simply and in very large numbers. because of this, field maintenance is no longer really necessary, except to store the SUE units and to monitor their shelf life by expiration date only. Because the logistics is then similar to that of the storage of soap, ~Dn~ulition or other disposable items, the corrrnunications system of the invention will be seen to obviate the need for, and updating of, extensive field documentation, main-tenancy and test facilities, and the spew training of user and maintenance personnel. it the same time, the introduction and updating of technical dock-mutation testing and personnel training will be seen to be required only at 1 :lZ3778~
the manufacturing facility. The most expensive operation in conventional electronics manufacturing, that of testing, will be reduced to the testing of random samples during any production run. As such, the user only needs to know the expected value of the yield of operational devices avid its distributiorl in any given manufacture.
The MESS user and interfacing units shown in FIGURES 3 and 4 include essentially similar elements as shown in FIGURE however, the hardware illustrated in these two drawings differ in the requirement of exhibiting a high Reliability characteristic -- such that for example, the chip containing the illuminates of FIGURE 1, in the constructions of FIGURES 3 and 4, would be conventionally encapsulated and fully tested. Additional testing expenses associated with these constructions, however, can still be largely eliminated to¦
the extent that the MESH units employed are available from the random sampling testings carried out in the original MESH production. reference numeral 60.) ! According to user requirements in the communications mode of operation the input/output circuit of the individual MESH unit 60 might be required to interface with external equipment and/or circuitry -- such as analog-to-digital and digital-to-analog converters, crypt devices, sensors and analyzers of biological parameters (for user authentication, for example), special-purpose sensors, processors, actuators, transmitters, interfaces to other systems, etc. !
As an example (and referring to FIGURE 3), the chip can be interfaced with user peripherals such as an authentication unit 62, analog/digital conversion circuitry 64 for voice in/output, data terminal equipment 66 such as a keyboard i I
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I to or wit trout do splay or a graphics digitizing pad, and a it me do splay 68. (As indicated, the unit is also powered with its own high reliability battery 70.) If user requirements exceeding the normal MISS capability, but not exceeding the MESH specification, are to be accommodated, additional external equipment can beadded, as shown in FIGURE 4 -- such as a multiplexer-demultiplexer I for multi-channel operation, crypt equipment 74 to provide for data security, a coder/decoder 76 to improve error rate and, if needed, an interface 78 to make non-MESH hardware compatible with the ASH input/output circuit.
In operation, and referring to thy flow diagrams of PHARISEE 5-10 --, when sufficient battery charge is sensed by the charge sensor 40 of FIGURE 1, appropriate power is supplied to the processing circuitry there shown and the functions are initialized, switching "on" the central processing unit 10, its peripherals and the receiver indicated, also actuating the system monitor and clearing the various counters and buffers. The central processing Kit then checks the receiver output for incoming Calls (KIWI?). If a call is received !
(500) the central processing unit then checks whether the call came from a validsource (OLD SAC?), i.e., whether the authentication code in the header of the unit is correct. If that is not the case, the central processing slit then I, returns to label 400, to await an authentic incoming code signal. Upon reception 20 11 of a valid incoming Cole the central processing unit checks for mode ,1 1 ,, .
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information in the header (M), and in the event of rode branches, couples it to label 3000 (see FIGURE 9). The some sequence occurs if the next check (carried out in the unit BUY MTY?)shows that there are untransmitted message units or packets (P) in the R3-mode buffer, indicating that the buffer is not empty.
However, if the buffer is indeed empty, the next question in the flow diagram is whether the message units have been handled before and its header (H) is therefore stored in memory I. If is found in I (label 700) and the incoming H does not have an acknowledge request code (NO 2) in its network function field, the program then branches back to the label 400 to check again -- otherwise, it will check if the old H in I already contained the acknowledge request OF 2) function. If an H is found in M, and an acknowledge request NO 2) is located, a branch to label 400 occurs (NO 2 being able to override "H in I only- once). If no 2 was in the stored H, the present H containing NO 2 will override the stored H (H -if M), and the program then continues at label 1000 (FIGURE 6). With a negative "I in M" test (label 900 in EI~JRF. 5), a further test (H in V) reveals whether the message header (H) is held in a temporary register (V). In the negative case, the incoming is written into V, and a counter is set to a maximum allowed for incoming Koalas (SO CUR).
This leads to label 950, which is followed by decrementing the COWAN in counter once, and a return to label 400.
If, on the other hand, H was already in the register V, the OAKEN count or is tested (KIWI CUR = 0?). If it is 0, a branch to label 1000 occurs, other wise label 950 is reached. If the CQI-test was negative (label 600), a test would have been made whether the message header (H) was held in the temporary register V (H in V?). If the test turned out negative, branching back to 400 occurs. In the affirmative case, H was received before, and an additional test determines whether too much time (MOE?) elapsed since the last KIWI, then label 650 is reached, but if not, return to label 400 occurs.
At label 650, it still nut be tested whether the mode required in the lZ3`778 header (H), as held in the register (V), is the wide-path random walk (R2?~.
In the affirmative case, label 800 is reached after storing the V-content in an appropriate location in memory My=); in the negative case, label 800 is reached immediately. After that, V is cleared (CUR V), and the program returns to label 400.
Lo Flume 6, at 1000, the present reading of the real-time clock (RTC) is written into the appropriate H-field in the V-register. Then the V-cantent with an acknowledge CQ-NF3 functional code inserted is transmitted (CQ-acknowl-edgement). The next decision point is reached (in practice after a suitable time delay), when a test is made whether H, as transmitted between labels 1000 and 1100, together with P and a send-P function NO 5 have been received (P/NF 5 LO?). If this is not the case, the program tests for a request for random time delay CON 4 LO?). East of such a request causes a random wait beginning at the present RTC-time (Eureka + DEL), followed by a return to label 1000. If no NF-4 "delay request" was received test is made whether the present PUG
time minus the time at which OF 3 was sent exceeds a ~ximum (RTC-TV IVY.
If this is affirmative, it is assumed that the service-requesting SUE
unit selected another MISS unit to handle its message packet and the program returns to 800; otherwise, the V/N~F 3 - transmission, etc. is repeated by no-turrlin~ to label 1100.
If the (P/NF 5 IN?) test result was affirmative, i.e., that the message packet (P) is then in this 'ASH units P-buffer, label 1200 was reached Lowry the hop count (I) in the header (H) is incremented by 1 (I = I + 1). If the new I then equals the m~cu~im (I = MY.?) specified for this Misfiled, fur-then P-travel will be prevented. As will be understood, it is only necessary to test whether D2-service was requested (Do?) -- where user units, i.e., data terminals (D) have assigned, e.g., alpha-numerical identifiers which can be changed as required, and which are needed to identify source (Do) and destine-lien (Do) of a message message omit or packet UP) in the n~ssage header (H).
he pr~gr~n coos into the batcery-che rut m e (2600) if this was not the gas i 1~3'7~
-- otherwise into (1250) --, where it will notify the previous MISS unit of a lost packet (P) by transmitting V/NF 8 first, and then run the battery check According to the program, a battery check is always performed at the end of a program loop, if that program segment contained steps involving high battery drain, i.e., operation of the transmitter.
IJithout an affirmative DMAX-test result (1300), it is still necessary to test for D2-service. If no (Do) message destination is requested, Precept lion can then be acknowledged TV 6), otherwise this is postponed. The next steps store the V-content in M, inserting the NO 1 "sending CQ function" into the register (V)(1400) and setting the transmit-CQ counter (SEC CUT prior to reaching label 1500.
At label 1500 (FIGURE 7), the ASH unit begins its attempt to transfer the packet (P) to the next MISS unit (designated Us, with its V-register design noted as V2). The first MISS unit (U) transmit a Cole (VNF 1) once, decree vents the Kowtow counter DO OKAY CUR), waits pharaoh a signal-round-trip time (not shown) and then tests for reception of a CQ-ackncwledg~ment (V2/NF 3 r1?) which could come in after the first Call provided Us was identical with I the addressee (label inn FIGURE 7). Usually, this will not be the case all the program will branch to label 1600 (FIGVR~ 8). If, however, label 2000 was reached, the V2 (the if with Use RTC-time) is stored in V and toe transmit-P counter is set (SUP CUR). At label 2100, P with the V-ccntent and NO 5 "send P" function is transmitted (P + V/~JF 5) and the P-out decrement Ed once (DEW PO CUR) to reach label 2200 where a test is made for P-acknowledge~ent (V2/NF 6 I If this is affirmative (label 2500), I must be checked again.
If it was requested, P had not been acknowledged between labels 1300 and 1400 and must be acknowledged now (V/NF 6), followed by a WriteNow to the battery-check routine 2600.
A negative V2/MF 6-test result (label 2300), an the other hand, require a test whether repeat of P-transmission was required by Us (V2/NF 7 IN?), in-dilative of a repeat of the packet (P) requested. The affirmative case simply Aye results in a return to label 2100, but in the negative case (lube]. 2400), the Pout counter is checked (PO CUR = 0?). If it is not zero yet, then return to label 2100 occurs. If the noisomely permissible number of P-transmissions has been exhausted, then the program will either return to the battery check routine 2600 or, in the D2-case, notify the previous ASH unit of a lost packet (P) (label 1220, FIGURE 6).
The case of the negative V2/~ 3 - test result (label 1600) is shown in FIGURE 8. A test is made whether a V2, garbled by another carrier, has been received ((V2)/CS run?). This would require a delay request (NO 4) in the register TV an a return to label 1400 (FIGURE 6). If nothing has come in (label Thea O?O-counter is checked -- and if it has not yet Len down to zero, return to label 1500 is indicated. If it is zero (label 1300), it is necessary to test for the NO 2 "acknowledge request", i.e., whether an ac~lowl-edge-request series has been transmitted previously. If this is the case, the program returns to label 1220; and, if not, then the NO 2-request is inserted into the register (V), the Kowtow counter is set to a n~ber adequate for 2 -transmissions, and the program returns to label 1400.
An R3 service request or unfinished R3 business diverts the progrc~n to label 3000 (FIGURE 5), continuing it from there, as shown in FIGURE 9, where first the memory is searched to determine whether it contains .'~ of the in-coming call (!~ DUN I?). If this is the case, the program returns to label 400 of FIGURE 5. A negative test result (label 3100, however) requires a check whether the padcet (P) is held in the P-buffer. If P is fund in the buffer, it was not errOrfree and the incoming copy of P is used to correct errors in the previous copy. If the message packet (P) was not yet in the buffer (3200) on the other hand, and there is still space in the buffer, P is read into the buffer (3300). If, however, the buffer were full (BUY FUR?), then the inks-in message packet (P) cannot be handled at this time, c1nd the buffer address of the P that has been in the buffer the longest is pointed at by a transmit-flag (XFL) register AL TAX) ion idiot ire stussicn, by label 3600 ~23''77~) , I .
If label 3300 was reached, and there is a message packet (P) in the Buffer for which the error detection is zero (ED = 0?), the "XFL" flag is set topoint at that packet (P) (3400), followed by the label 3600.
If all P in the buffer contain at least one error (at unit 3500), a test is then made according to the program, whether one of the P has reached themaximally pennissible storage time (TAX ?). In the affirmative case, the header(H) of that packet (P) is then marked with an error flag (ELF - H) and "XFL" flag¦
set to point to its address, followed by the label 3600. A negative Attest Returns the program to the point 400 of FIGURE 5.
I The Retransmission sequence begins at point 3600 in Flyer 10, with a single transmission of the header (H) us pointed to by the "XFL" flag. After that, the transmit counter (XMr CUR) is set (SEX CUR) and the buffer content indicated by "XFL" is transmitted US (XFL)). Then, the transmit counter is checked -- and, if it is zero, H is stored in memory (~) and the progr~n continues to label 2600. If the counter is not yet zero, it is decrement Ed once (DEW CUR) and the transmission repeats itself again.
As will thus be seen, and as will be understood by those skilled in the art, the MESH system elements thus perform the following functions:
a. In the recruiting mode, the elements receive incoming signals and validate them according to their identifying and control code (the latter indicating a recruiting signal). Depending Oil the quality of the cleanly (e.g.noise, attenuation, multi-path distortion, etc.) between the signal source and the receiving unit, a certain number of calls would be required before enough error-free signals would match the count in the preset counter of the unit.
'' ! I
. .
,,"
~3`7'~
rho system element wall then issue an acknowledgement to the calling station, thereby silencing it, and will start transmitting call signals of its own.
b. In the communicating mode, on the other hand, the system element will relay only messages from terminal stations which were the originators of the original calling chain. However, it will accept and acknowledge recruiting calls from the other terminal stations involved, provided their call is addressed to one of the terminal stations of the Issue unit in question. The system element will thus store addresses of all terminal stations l with which it communicates.
if On the other hand, the So unit operates upon the receipt of a proper command, and in response, will switch its code generator to any other code and/or change its preset counter number as the case may be. In such instance, if the system element in the communicating mode then attempts to relay a message to the next system element in the network, and that unit does not acknowledge the address, the transmitting system element will notify the message originator of a break in the chain, and then switch to its recruiting mode.
Message routing in the ESSAY system is thus determined by the operating mode of its individual unit. Such mode can be selected from a menu, according id tithe invention, in firmware by the appropriate code in the header (H). Two basic 20 Al code schemes according to the invention can be identified as the "random walk"
(Al) and the broadcast mode (K3~ -- but can be modified further by a "wide-path"
random walk (R2) and a form of end-to-end control for Al and R2 by an automatic message acknowledgement according to message destination and source llidentification (DO, Do, respectively), resulting in routing schemes Al, Do and ;~R2, DO, for example.
Al The user's data terminal equipment, D, allows for the selection of one ., I .
I
Ii. I
If if _ 1~3' i''7~0 ¦ operating de from a series available to that particular user, thereby giving¦ a greater choice of operating modes to a higher-priority user than to a lower-¦ priority user. The terminal equipment (D) will then place an operating code, ¦ OPT, into the designated field which identifies the routing scheme correspond-in to the operating mode under which the message (P) was issued. Such code ¦ can be appended by a sufficient number of bits to identify various network management functions (NO) such as pa) Send CQ; (b) Acknowledge Pickiest; (c) Acknowledge CQ; (d) Delay Request; (e) Send P; (f) Acknowledge P; (g) Pickiest l Repeat of P; and oh) Loss-of-P Notification in D2-Mode.
¦ In this manner, the Al and R2 modes support P-travel within a ASHfield from one originating data terminal (D), i.e., Do, to one destination (Do) via a random walk that links Do to a succession of MESH units terminating in Do. P-transfer is initiated by Do by means of repetitive Koalas which con-sit of H with the appropriate operating code (OPT). Any neighboring IFS
unit that is not busy with other tasks will then receive the CQ and compare incoming H-fields with its own stored validation and authentication codes.
The process then repeats until a MESH unit achieves a predetermined number of matches, which could either be part of the header information or stored in firmware. The number of required matches serves as a threshold for ~4-ackn~l-edgement from the ASH unit. Since that unit which receives the Calls with the least interference, attenuation and delay will acknowledge them first, the message will be made to travel over the best available channel, from the oft-jointing unit (Do) to its so-linked neighbor. Acknowledgement then consists simply in a retransmission of the header by that neighboring unit, along with the network function indicating ackncwledp,ement plus the neighboring unit localtime of retransmission. Reception of an acknowledgement thus causes the originating ASH unit to terminate its Killing sequence, King it impost-isle for most other neighboring MUSH units to reach their thresholds for in-coming Koalas If, however, more than one Masonite has reached the C?
threshold, they will then compete for the same message packet by acknowledgit~
l 1~3'^~
the CQ.
But, in accordance with the present invention, there exists three lea-lures in the N and R2 modes to help break such a contention case between neighboring So units -- (l) Carrier Sense Multiple Access (COMA); (2) Local-Time Tag; and (3) Random Acknowledgement Delay.
KIWI is used in the MESH units of the invention, and operate in such a way that a transmitter at an originating location or at a neighboring location can be switched on only after the receiver of that particular unit was unable to detect any other carrier on the air. Depending upon propagation delays be-tweet the originating unit and contending SUE units, SHIM may be sufficient to break acknowledgement contention. however, if neither of the contenders did detect the other's carrier in the time required to block their own trays-mission, they may acknowledge about the same time. Since each acknowledgment will be supplemented by the local time of the acknowledging SHEA unit, and these times are highly unlikely to be the same, the received acknowledgements can be ascribed to particular MESH units by the originating system element, providing the original unit's processing time is less than the difference in arrival times between acknowledgements. In this case, the message would be addressed to that MESH unit whose acknowledgement arrived first, i.e., the message would be transmitted with the header supplemented by the local time of the addressee. Any contending So unit would then refuse to handle the mess-age packet by simply ignoring it.
If acknowledgements arrive at the originating unit so close within each other that there is not enough processing time to read and separate the local times, the acknowledgements will then tend to destroy each other. In this case, the originating unit will send a repeat CQ according to the invention, this time with the management function NO indicating a random delay request. Con-tending message units receiving this CQ will then wait a rundown time interval before attempting acknowledgement. The entire process then repeats until con-tenders are separated either by COMA, or by local-time differentiation. After ; -18-I 3 7 To that, the originating unit will send its message packet to the first ISSUE unit in time, which then can be assigned a designation (Us), the originating unit having the designation (Do).
(In the R2 mode, all MESH units use) which received a copy of the I
but did not become Us would store I and from then on, Rufus handling a P be-longing to the header (~) .) After Do has transmitted its message packet to Us, it has completed its task, and Us would then attempt to dispose of that message packet by repeating all of the previously described Dl-functions, i.e., the message packet (P) would be handed to another Ho unit (U) become Us. At that time, Us would have stored H which prevents it from reaccepting that particular packet (P).
The packet (P) tlould then travel from Us to Us, and so on, ctlong a path which resembles a "random walk". As will be appreciated, the loop cannot come back on itself, because no previous handler of the message packet (P) will handle it again, with one exception -- which may arise when P travels towards the edge of the SHEA field in such a way that it wiped out all return possibilities behind it: in that case, the Koalas of the ?IEShT unit nearest to the field edge will not elicit an acknowledgement, and only then will the MOE unit place an acknowledge request into the NO field and reissue Koalas Such "acknowl-edge requests" will override the rehandling refusal in any previous Ml~:S~I unit, with the packet (P) then traveling from Us to fin I whereupon Us 1 removes the "acknowledge request" and tries to pass on the packet (P) in the usual way.
If this fails, an attempt will be made to reinstate the acknor.Tledge request, etc. According to the construction of the units in the block diagram strikeout any I unit that has handled a packet twice will be prevented from handling it a third lime under any circumstances, so that the packet (P) us forced away from the edge of the flesh field.
wherever a Cole is received by a data terminal for which it is desk lined (Do), then that terminal will acknowledge the I irlmediately in order to l terminate the message packet -travel.) SUE
According to the invention, the message header (~) also has a field for the accumulative hop count. This is a number which is incremented every time the message packet (P) is received by a MY unit (U). Another field in the header (H) contains a number which determines a maximal hop count. whenever the accumulative equals the maximal hop count, no further I will be issued by the receiving hush unit, so as to assure that the packet which does not reach the desired destination after a number of trials will be deemed unreasonable for the ¦
size of the MESH field, and will be abandoned. If the packet priority warrants Kit, a Deporting mode can be included to notify the originating unit of the lost packet, which could then be retransmitted, and in a R3-mode.
Such R3-mode is a broadcast one in which the message packet exhausts all the resources of the ASH field once. In this mode, it is virtually impossible for an existing intended destination not to be reached by the packet, and is very useful for reaching classes of destinations, i.e., all binary digits within the field so as to sub-divide the class. In this mode, the originating unit only issues a single Call to initiate all neighborir~, unoccupied MUSH
units to the R3-mode. This is followed by repeated transmissions of 11-P
sequences, which are to be accepted by each Howe unit in the mud, putting it lint a buffer. Each unit would continue accepting the packet (P) until all terrors are corrected, or no further packets (P's) are received. it that time, the MESH unit would store the header to bar rehandling of the packet (P), and proceed as Do, the originating station, did before. In this fashion, the message , packet will travel as a single expanding ring around the originating station, an will even travel backwards if a MY unit has been missed, either due to an obstacle or because of temporary non-availability. Such feature makes it possible, therefore, for two or more, P-rings to penetrate without annihilating teach other. Only at the boundaries of the ESSAY field, would such P-ring be destroyed As thus described, certain advantages will be definitely seen to exist I Jo if l ~L'Z3~77~
- I utilizing the cwn~unicaticns system of the present invention. First, the soys-tern will be seen to be a totally probabilistic one in every respect, consisting of a set of system elements of which only a subset, c~eterrnined by the product lion yield in that particular set, would be operational at any given time. A
still smaller subset, determined by battery-charge conditions and message-traffic loading, would be taking part in system functions. ~11 system elements temporarily or permanently not engaged in system activities, would still act as decoys to foil search and collect operations.
Secondly, direction finding, or tracing, of cc~nunication paths will be seen virtually impossible due to the random and continually changing disturb-lion of active system elements. terminal stations will be seen not to have any specific signature which could allow one of them to be distinguished from the system elements being used.
Also, the line-of-sight operation introduces no detrimental effect since all line-of-sight obstacles simply act as supports for the system eye-mints, thereby proving a disadvantage to a potential jammed. ~ltipath effects will be seen to result in negligible multi path spread, as well, due to the short average distance between system elements in operation. In because the transmitter power of active system elen~nts is so low as to be nearly India-tinguishable from a widely dispersed low-power-random-noise source, convention-at systems that operate in the same geographical area will experience only a slight raise in background noise which is not likely to interfere with their normal function. Conversely, a strong conventional emitter within the ASH
field, operating in the same frequency band, would incapacitate only a relative lye small number of SUE units. message traffic jollied simply route itself crane the disturbance.
s will be apparent, the ASH construction is eminently suitable for communications and control in geological and jungle exploration, mining opera-lions, explosives removal, nuclear and toxic removal and clean-up operations, fir ghting, etc. It it a desirable system for disaster preparedness em d for establishing c~nmunications during an emergency and after a disaster has occurred that wiped out all conventional means of communications. Necessary terminal stations, not larger than a wrist watch, can easily be airdropped together with the ISSUE units, e.g., by dangling them from small marker pane-chutes or long, brightly colored ribbons on which could be printed the open-a tying instructions. SUE terminals could be dispensed as part of survival packages for sea and air travel and transport crews, forest and park rangers, etc. ILSH is also particularly suitable for all purposes where the user must not be encumbered by clumsy equipment or restricted in his movements by line-lo of-sight requirements. It is an ideal system for the communication Thea, and control of, autonomous or semiautonomous robots.
Intelligence and reconnaissance operations in hostile territory could similarly benefit according to the system of the invention -- as an operator in enemy territory is only called upon to use a transmitter with extremely low output power, just sufficient to enter the nearest neigliboring So unit.
Interception of such ITCH communication, however, would give no clue as to the location of the terminal station, as previously indicated. And, to prevent "spoofing" -- i.e. an unauthorized entry into the system --, the terminal stay lions can be linked to vital functions of their carriers in use in the commune cations network -- such as to a biological-electrical signature, in the nay lure of electrocardiogram, electroencephalogram, or other available identify-in indicia, so as to grant access to the system only to authorized users.
Cryptosecurity can be introduced rather easily either by storing enough crypt tokens in a read-only memory of each unit, where, e.g., the message n~ber could determine the key selection, or by conventional means eta m at to the ASH system. Code brealcing attempts would take longer than the life time of a particular SUE field.
initial charging of the batteries could be accomplished inductively through the deployment container by replacing the connection to the solar battery with a connection to an inductive antenna loop via a rectifier diode.
.1 I 1~3'7~U
Upon deployment this connection could be broken, erg., by an air-triggered exothermic chemical reaction which would also fuse the battery terminals to the solar battery. This same action could be used to initialize the system units and synchronize their clocks.
While there has been described what is considered to be a preferred em-bodiment of the present invention, it will be readily appreciated by those skilled in the art that modifications may be made without departing from the scope of the teachings herein. For at least such reason, therefore, resort should be had to the claims appended hereto for a correct understanding of the 'I in
Claims (31)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A radio communications system comprising:
a multiplicity of randomly scattered self-contained relay transceiver stations which automatically organize themselves to form a relay chain capable of transporting radio message between two user terminal stations so long as the distance between said user stations is bridged by said relay stations in line-of-sight proximity with each other:
each relay station including an antenna, a receiver, a transmitter, means for switching said antenna between said receiver and transmitter, a programmable frequency synthesizer connected to said receiver and transmitter, a signal demodulator connected to said receiver and synthesizer and supplying a demodulated signal, an input/output means connected to said demodulator and synthesizer, a central processing unit connected to said input/output means, memory means connected to said central processing unit, clock means connected to said synthesizer and central processing unit, a modulator connected to said transmitter and to said synthesizer and input/output means, a transmitter switch connected to said antenna switch and to said transmitter and modulator and input/output means, and means supplying power to said input/output means.
a multiplicity of randomly scattered self-contained relay transceiver stations which automatically organize themselves to form a relay chain capable of transporting radio message between two user terminal stations so long as the distance between said user stations is bridged by said relay stations in line-of-sight proximity with each other:
each relay station including an antenna, a receiver, a transmitter, means for switching said antenna between said receiver and transmitter, a programmable frequency synthesizer connected to said receiver and transmitter, a signal demodulator connected to said receiver and synthesizer and supplying a demodulated signal, an input/output means connected to said demodulator and synthesizer, a central processing unit connected to said input/output means, memory means connected to said central processing unit, clock means connected to said synthesizer and central processing unit, a modulator connected to said transmitter and to said synthesizer and input/output means, a transmitter switch connected to said antenna switch and to said transmitter and modulator and input/output means, and means supplying power to said input/output means.
2. The system of Claim 1 wherein said relay stations each include rechargeable power means.
3. The combination of claim 2 wherein said relay stations are enclosed in a foldable structure that forms a carrier upon which all elements of said relay station are deposited.
4. The combination of claim 3 wherein said carrier has extensions at each end that form leg-like support structures in such a way that a number of said structures support said carrier while the remaining number of said structures extend away from the supporting surface.
5. The combination of Claim 4 wherein each of said support structures is the substrate of conductors forming antenna elements.
6. The combination of Claim 5 wherein each of said support structures is also the substrate for a solar cell or a battery of solar cells.
7. The combination of Claim 6 wherein the carrier frequency of the transmitter of said relay station is high enough as to allow for the minaturization of said antenna elements.
8. The combination of Claim 7 wherein said power means is a rechargeable battery having its components distributed over part of said carrier.
9. The combination of Claim 8 wherein all the remaining components of said relay station are combined in one or several hybrid or integrated circuits and said circuits are attached to, or imbedded in, said carrier.
10. The combination of Claim 9 wherein the tips of said support structures are covered by an adhesive.
11. The combination of claim 1 wherein each said central processing unit includes programming means responsive to radio message recruiting calls by a first terminal or neighboring relay station to accept a message and issue recruiting calls of its own in order to transfer the message to another neighboring relay station or to the second terminal.
12. The combination of claim 11 wherein said programming means includes a program which operates to select the one out of several neighboring relay stations or terminal to which the electromagnetic propagation path is least obstructed by noise, attenuation and multipath effects, the selected relay stations completing a link between said first and second user terminal stations, and the unselected stations remaining inactive.
13. The combination of Claim 12 wherein a read-only memory stores said program and all data necessary for the operation of said communications system including the operating protocols.
14. The combination of Claim 13 wherein said read-only memory also contains a cryptocoding and decoding program and a protocol for the assignment of cryptokeys.
15. The combination of Claim 3 wherein a multiplicity of said relay stations is layed flat on top of each other in stacks that fill said carrier from which said relay stations can be emptied, whereupon they assume a predetermined shape by virtue of prestressed areas in the material of said carrier.
16. The combination of Claim 15 wherein said carrier is of a nonmetallic material.
17. A radio communication system comprising:
a multiplicity of randomly scattered self-contained like relay transceiver stations which automatically select particular ones of said relay stations to complete a relay link capable of communicating radio messages between two user terminal stations so long as the distance between said stations is bridged by said relay stations in line-of-sight proximity with each other; each relay station including an antenna, a receiver, a transmitter, means for switching said antenna between said receiver and transmitter, a programmable frequency synthesizer connected to said receiver and transmitter, a signal demodulator connected to said receiver and synthesizer and supplying a demodulator signal, an input/output means connected to said demodulator and synthesizer, a central processing unit connected to said input/output means, said central processing unit being capable of initiating and discontinuing communication with other stations independent of control from a user station upon receipt of a predetermined signal including programming means for automatically selectively responding to received message recruit-ing calls and transmitting an acknowledgment signal to the sender and transmitting recruiting calls to another relay station to complete a link for transfer of messages between said user stations independent of and without selection from a user station, memory means connected to said central processing unit for storing all predetermined programming modes of said programming means, clock means connected to said synthesizer for controlling the frequency thereof and to said central processing unit, a modulator connected to said transmitter and to said synthesizer and input/
output means, a transmitter switch connected to said antenna switch and to said transmitter and modulator and input/output means, and means supplying power to said input/output means.
a multiplicity of randomly scattered self-contained like relay transceiver stations which automatically select particular ones of said relay stations to complete a relay link capable of communicating radio messages between two user terminal stations so long as the distance between said stations is bridged by said relay stations in line-of-sight proximity with each other; each relay station including an antenna, a receiver, a transmitter, means for switching said antenna between said receiver and transmitter, a programmable frequency synthesizer connected to said receiver and transmitter, a signal demodulator connected to said receiver and synthesizer and supplying a demodulator signal, an input/output means connected to said demodulator and synthesizer, a central processing unit connected to said input/output means, said central processing unit being capable of initiating and discontinuing communication with other stations independent of control from a user station upon receipt of a predetermined signal including programming means for automatically selectively responding to received message recruit-ing calls and transmitting an acknowledgment signal to the sender and transmitting recruiting calls to another relay station to complete a link for transfer of messages between said user stations independent of and without selection from a user station, memory means connected to said central processing unit for storing all predetermined programming modes of said programming means, clock means connected to said synthesizer for controlling the frequency thereof and to said central processing unit, a modulator connected to said transmitter and to said synthesizer and input/
output means, a transmitter switch connected to said antenna switch and to said transmitter and modulator and input/output means, and means supplying power to said input/output means.
18. The combination of claim 17 wherein said pro-tramming means includes a program which operates to independently select the one out of several neighboring relay stations or terminal to which the electromagnetic propagation path is least obstructed by noise, attenuation and multipath effects and establishes a threshold of error free incoming signals to activate the receiver and transmit said acknowledgment signal, the selected relay stations completing a link between said first and second user terminal stations, and the unselected stations remaining inactive.
19. The system of claim 18 wherein said relay stations each include rechargeable power means.
20. The combination of Claim 19 wherein said relay stations are composed of a foldable structure that forms a carrier upon which all elements of said relay station are deposited.
21. The combination of Claim 20 wherein said carrier has extensions at each end that form leg-like support structures in such a way that a number of said structures support said carrier while the remaining number of said structures extend away from the supporting surface.
22. The combination of Claim 21 wherein each of said support structures is the substrate for conductors forming antenna elements.
23. The combination of Claim 22 wherein each of said support structures is also the substrate for a solar cell or a battery of solar cells.
24. The combination of Claim 23 wherein the carrier frequency of the transmitter of said relay station is high enough as to allow for the miniaturization of said antenna elements
25. The combination of Claim 24 wherein said power means is a rechargeable battery having its components distributed over part of said carrier.
26. The combination of Claim 25 wherein all the remaining components of said relay station are combined in one or several hybrid or integrated circuits and said circuits are attached to, or imbedded in, said carrier.
27. The combination of Claim 26 wherein the tips of said support structures are covered by an adhesive.
28. The combination of Claim 18 wherein a read-only memory stores said program and all data necessary for the opera-tion of said communications system including the operating proto-cols.
29. The combination of Claim 28 wherein said read-only memory also contains a crypotocoding and decoding program and a protocol for the assignment of cryptokeys.
30. The combination of Claim 20 wherein a multi-plicity of said relay stations is layed flat on top of each other in stacks that fill said carrier from which said relay stations can be emptied, whereupon they assume a predetermined shape by virtue of prestressed areas in the material of said carrier.
31. The combination of Claim 30 wherein said carrier is of a nonmetallic material.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US65148384A | 1984-09-17 | 1984-09-17 | |
| US651,483 | 1984-09-17 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1237780A true CA1237780A (en) | 1988-06-07 |
Family
ID=24613016
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000485207A Expired CA1237780A (en) | 1984-09-17 | 1985-06-25 | Radio communications system eith randomly scattered, automatically organizable relay stations |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1237780A (en) |
-
1985
- 1985-06-25 CA CA000485207A patent/CA1237780A/en not_active Expired
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