Abstract:
Light sources are affixed at appropriate positions in a multilevel structure or in an obstructed environment. The light sources generate modulated light signals, such as controlled light-emitting diodes, which identify the positions of the light sources by their three-dimensional global positioning coordinates and/or equivalent representation that specifies their in situ locations in the environment. Mobile communication devices, upon receiving the light signals, can derive spatial positioning information and transmit such information to a remote location, such as an emergency response system.

Description:
RELATED APPLICATIONS 
     This application claims the benefit of the earlier filing date under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 61/053,198 filed May 14, 2008, entitled “System and Method for Determining Position Information Via Modulated Visible Light,” the entirety of which is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to communication devices, and more particularly to determining with greater accuracy the location of communication devices. 
     BACKGROUND 
     Lifestyles have become increasingly reliant on mobile communications. Wireless communication devices, such as cellular phones, laptop computers, pagers, personal communication systems (PCS), personal digital assistants (PDA), and the like, provide advantages of ubiquitous communication without geographic or time constraints, as well as the added security of being able to contact help in the event of an emergency. Mobile terminals have been equipped with versatile location-awareness technologies, such as global position system (GPS) tracking features. Such features enable a consumer to monitor the position of the terminal as well as transmit its location to emergency response personnel during emergency situations. 
     The position of a device is monitored through GPS technologies that utilize a system of orbital satellites to determine positioning information. The constellation of satellites will transmit very low power interference and jamming resistant signals to a wireless device GPS receiver, which may receive signals from multiple satellites at once. The GPS receiver may determine three-dimensional spatial positioning information from GPS signals obtained from at least four satellites. These GPS signals are transmitted over two spread spectrum microwave carrier signals that are shared by the GPS satellites. Measurements from satellite tracking and monitoring stations located around the world are incorporated into orbital models for each satellite to compute precise orbital or clock data. Thus, a wireless device employing a GPS receiver identifies GPS signals from at least four satellites, decodes the ephemeris and clock data, determines a pseudo range for each satellite, and then computes the position of the receiving antenna of the GPS receiver. Accordingly, the spatial position of the receiving antenna can be determined with great accuracy and convenience. 
     Unfortunately, since GPS signals are transmitted over two low power spread spectrum microwave carrier signals, the GPS receiver must have an unobstructed “view” of the GPS satellites. Indoor environments, e.g., buildings, cellars, edifices, garages, pavilions, or other urban settings, obstruct the “field of view” of the GPS receiver, and GPS tracking becomes unreliable. Tracking is unavailable when the GPS signals are too weak or cannot reach the GPS receiver. 
     Conventional location-awareness technologies are further limited by an inability to identify the vertical location of a device in a multistory building. While planar positioning may be obtainable, there is no provision for defining accurate three dimensional spatial coordinate positions. Emergency response personnel can arrive at an appropriate address in response to an emergency call, but lose valuable time to precisely locate where in the building help is required. 
     Accordingly, a need exists for positioning tools and methodology that enable users in obstructed areas to determine more accurately and/or report their positions. The particular need to derive absolute three-dimensional position can be of critical importance. 
     DISCLOSURE 
     The above described needs are fulfilled, at least in part, by fixing light sources, such as visible light sources, infrared light sources, etc., at appropriate positions in a multilevel structure. The light sources generate modulated light signals, for example by means of light-emitting diodes, which identify the positions of the light sources. Large buildings may include a plurality of spaced light sources on any given floor level. The spatial positioning information may include three-dimensional global positioning coordinates of the light source, including latitude, longitude, and altitude, or equivalent representation. The signals may include codes that identify the floor level of the associated light source. Light signal generation may be implemented by on-off keying with application of direct-sequence spreading or Manchester coding to a light source. 
     Communication stations, which may be mobile stations, are equipped to receive light signals generated and transmitted by the light sources in their proximate respective vicinities. A receiving station has the processing capability to derive the spatial positioning information from a received light signal. This information can be displayed at the receiving station. The light signal may be received by a camera in a mobile station device, a charge-coupled device of the camera then converting the light signals to electrical digital signals. 
     The communication stations can generate emergency alert notification for transmission to a remote emergency response system. Transmission can be initiated automatically or by human intervention. Spatial positioning information, derived by a station from a light signal received from a proximate light source, can be included in the transmitted emergency alert notification. An emergency response team can, thereby, accurately pinpoint a location within a large building based on included information corresponding to floor level and/or specific position on the level, and, thus, optimize response time to the emergency. 
     Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein the preferred embodiment of the invention is shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawing and in which like reference numerals refer to similar elements and in which: 
         FIG. 1  is a perspective illustration of an indoor environment capable of providing mobile stations with positioning information through light communication, according to an exemplary embodiment; 
         FIG. 2  is a block diagram of a light source configured to communicate with mobile stations through light wave signals, according to an exemplary embodiment; 
         FIG. 3  is a flowchart of a process for transmitting positioning information via light communication, according to an exemplary embodiment; 
         FIG. 4  is a block diagram of a mobile station configured to determine positioning information via received light communications, according to an exemplary embodiment; 
         FIG. 5  is a flowchart of operation of a mobile station such as described with respect to  FIG. 4 , according to an exemplary embodiment; 
         FIG. 6  is an schematic illustration of a mobile station positioning information display, according to an exemplary embodiment; 
         FIG. 7  is a block diagram exemplifying a system capable of providing emergency alert notifications including spatial positioning information, according to an exemplary embodiment; 
         FIGS. 8A-8C  are flowcharts of processes for providing emergency alert notifications for the system described with respect to  FIG. 7 , according to an exemplary embodiment; and 
         FIG. 9  is a schematic illustration of an emergency alert notification presenting positioning information, according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Positioning tools and methodology are provided herein for enabling relative and/or absolute three-dimensional positioning information to be accurately determined through light communication, such as visible light communication, infrared communication, etc., when conventional location-awareness technologies, such as global positioning system (GPS) technologies, are unreliable or otherwise unavailable. Positioning information that is determined through light communication can be reported to emergency response personnel in the event of an emergency. Light communication techniques employing illumination sources, such as light-emitting diodes (LEDs), may be utilized to convey information. Since LEDs provide bright, power efficient illumination that is reliable, durable, and capable of modulation imperceptible to human beings, LEDs may be configured to provide adequate illumination, while simultaneously configured to convey information. LED light communication techniques, thus, may be utilized to assist or supplant GPS technologies while mobile station users are located indoors or situated in otherwise obstructed environments. 
     An indoor environment capable of providing mobile stations with positioning information through light communication is illustrated in  FIG. 1 . While light communication is described through modulated light emitting diode (LED) illumination, it should be appreciated that other suitable light sources capable of providing adequate illumination, while at the same time, capable of being modulated to convey information, are contemplated. 
     Indoor environment  100 , such as a building, cellar, edifice, garage, pavilion, etc., includes one or more light sources  101  and  103 , which may be visible light sources. The light sources may provide adequate illumination for environment  100 , as well wireless communication with mobile station  105  through one or more modulated light wave signals  107  and  109 . Mobile station  105  includes a detecting light-receiving unit  111 , such as a charge-coupled device (CCD), light-sensitive sensor, photodiode, etc., capable of perceiving or otherwise detecting signals  107  and  109 . Unit  111  may be a standalone component of mobile station  105  or may be included as part of a conventional camera (not shown) of mobile station  105 . Wireless optical communication system utilizing indoor LED lights are capable of communicating with mobile station  105  without hindering standardized lighting functionality. 
     Alternatively, visible light sources  101  and  103  may be indoor LED lights capable of modulating visible light waves that are imperceptible to human beings. For instance, light sources  101  and  103  can be modulated with an on-off keying (OOK) technique, wherein a “1” is carried as an on-pulse, and a “0” is carried by an off-pulse. Using a 7-bit coding scheme, light sources  101  and  103  can be configured to convey up to 128 distinct numbers, which, in certain embodiments, may be utilized to convey 128 levels (or floors) of a building. According to other embodiments, other modulation techniques may be utilized to convey more elaborate positioning information or other data for use by mobile station  105  to accurately determine its spatial position. For instance, modulation may be applied in a less than full on, full off keying technique, wherein the amplitude of a light wave signal may be slightly (or otherwise) varied to convey information. Variance in amplitude may occur at frequencies greater than a flicker rate perceptible to the human eye, such as around 20 hertz. However, faster frequencies of modulation are contemplated and may be employed to increase the rate of information transportation between light sources  101  and  103  and mobile station  105 . For example, modulation may occur within the ranges of kilohertz, megahertz, gigahertz, etc. Other techniques for modulation may include amplitude-shift keying (ASK), continuous-phase modulation (CPM), frequency-shift keying (FSK), minimum-shift keying (MSK), phase-shift keying (PSK), pulse-position modulation (PPM), quadrature amplitude modulation (QAM), and trellis coded modulation (TCM), as well as any other suitable technique. Further, the luminance of light sources  101  and  103  may be configured to comply with any conventional illumination standard, such as illumination standards for the movement and/or activity of pedestrians, machines, and vehicles within varied environments like construction sites, corridors, excavation areas, factories, kitchens, loading bays, offices, parks, plants, etc. 
     Mobile station  105  may embody any suitable wireless communication device, such as a cellular, satellite, or other wireless or radio phone with a multi-line display; a personal communications system (PCS) terminal that may combine wireless telephony features with data processing, facsimile, and/or data communication capabilities; or a personal digital assistant (PDA) that may include wireless telephony features, a pager, “online” access, web browsing, an organizer, a calendar, and/or a radio (AM/FM) receiver, as well as embody a mobile computing device capable of wireless communications, such as a laptop, palmtop receiver, or other appliance that includes wireless telephony features. Mobile station  105  may also be referred to as a “pervasive computing” device capable of communicating with other devices via short messaging service (SMS) protocols or other protocols that allow for simultaneous communications of voice, data, and/or video information. 
       FIG. 2  is a block diagram of a light source  200  that may be utilized in the exemplified embodiment of  FIG. 1 . Source  200  includes LEDs  201   a - 201   n , LED controller  203 , memory  205 , modulator  207 , and processor  209 . According to other embodiments, visible light source  200  may include one or more other components configured to execute the processes described herein for light communication. For instance, a communication interface  211  may be provided to receive information that is to be subsequently broadcasted by light source  200  through one or more modulated light wave signals. 
     Light source  200 , via LEDs  201   a - 201   n , may be configured to illuminate a space, as well as to emit modulated light wave signals, such as signals  107  and  109 . Processor  209  accesses memory  205  to obtain data corresponding to positioning information. This data is applied to modulator  207  to modulate the data into a light transmission signal, such as a visible light transmission signal, that is to be communicated to mobile station  105 . LED control signals are generated for driving LEDs  201   a - 201   n . Modulator  207  may apply direct-sequence spreading, Manchester coding, or other suitable methodology to reduce the impact of ambient light and signal interference. 
     The control signals excite LEDs  201   a - 201   n  which output illumination including at least one modulated light wave signal embodying or associated with positioning information, such as latitude, longitude, and altitude information. The positioning information may also include an address, floor, structure name, location name, etc. The modulated light wave signals may contain information for resolving the spatial position of mobile station  105 . For instance, the information may correspond to timing information and/or reference positioning information that is utilized by mobile station  105  to determine its spatial position. 
     Communication interface  211  may be utilized to initialize light source  200 . That is, communication interface  211  may be employed to input (or upload) data corresponding to positioning information to memory  205  and/or processor  209 . According to one embodiment, communication interface  211  communicates via any suitable wired (e.g., coaxial cable, optical fiber, twisted pair, etc.) and/or wireless (e.g., light wave, radio wave, microwave, etc.) communication medium. For instance, communication interface  211  may communicate over a power line communication system, the public switched telephone network (PSTN), the Internet, a wireless area network, a wired area network, or other suitable communication system, such as a short-range communication system, a near-field communication system, or a proprietary network of a service provider, such as a cable or fiber optic network. In particular embodiments, communication interface  211  may employ transmission technologies, such as asynchronous transfer mode (ATM), bluetooth, code division multiple access (CDMA), enhanced data rates for global evolution (EDGE), ethernet, general packet radio service (GPRS), global system for mobile communications (GSM), infrared, Institute of Electrical and Electronics Engineers (IEEE) 802.11, IEEE 802.16, satellite, transfer jet, universal mobile telecommunications system (UMTS), wireless fidelity (WiFi), worldwide interoperability for microwave access (WiMAX), and the like, as well as combinations thereof. 
     Accordingly, processor  209  may be configured to implement a user interface, such as a graphical user interface, for inputting data corresponding to positioning information to memory  205 . For instance, a networked portal, e.g., a webpage application, may be accessed and utilized to transfer data to light source  200  over one or more wired and/or wireless networks. Communication interface  211  may be employed to facilitate data transfer. 
       FIG. 3  is a flowchart of a process for transmitting positioning information via light communication in accordance with light source  200 . At step  301 , light source  200  obtains data corresponding to positioning information. Processor  209  may receive such data from memory  205  or via communication interface  211 . For instance, light source  200  may receive data over short-range communications via communication interface  211 . In exemplary embodiments, communication interface  211  may be configured to continuously “listen” for data transmissions; however, it is contemplated that other “listening” schemes may be employed, such as periodic, on-demand, etc. According to one embodiment, communication interface  211  employs a short-range (e.g., bluetooth) or near-field (e.g., transfer jet) communication mechanism, whereby light source  200  is initialized by a corresponding transceiver (e.g., mobile terminal) configured to transmit data corresponding to positioning information to light source  200 , as well as activate (e.g., turn on) light source  200  for light communications. Other modes of initialization are also contemplated, such as by the aforementioned networked portal. Accordingly, at step  303 , processor  209  ports the data to modulator  207 , which modulates the data into light transmission signals that are communicated to mobile station  105 . In particular embodiments, these light transmission signals are visible light transmission signals. Control signals can be generated to drive LEDs  201   a - 201   n . In step  305 , LED controller  203  utilizes the transmission signals and/or the control signals to drive one or more LEDs, such as LEDs  201   a - 201   n . Modulated light, such as modulated visible light, is transmitted via LEDs  201   a - 201   n , per step  307 . 
       FIG. 4  is a block diagram of a mobile station  400 , corresponding to mobile station  105  of  FIG. 1 . Location module  401  determines the spatial position of mobile station  400  via data received from light receiver  403 . Location module  401  can generate emergency alert notifications including spatial positioning information for transmission to a remote emergency response system or emergency response personnel. 
     Light receiver  403  includes detector  405 , demodulator  407 , and processor  409 . Modulated light wave signals, such as modulated visible light wave signals, are received by detector  405  and converted into data signals that correspond to the modulation of the received light waves. While not illustrated, modulated light wave signals may pass through an optical conditioner, such as an amplifier, filter, etc., before or after being converted into data signals by detector  405 . Detector  405  may be a charge-coupled device (CCD), a light-sensitive sensor, a photodiode, etc., included as a standalone component of mobile station  400  or as a component of a conventional camera of mobile station  400 . 
     Demodulator  407  demodulates the data signals received from detector  405  into corresponding transmission signals. Processor  409  converts the transmission signals into spatial positioning information or corresponding data for use by location module  401 . 
     Wireless headset  415  may be implemented for communication with a wireless controller  417  of the mobile station  400 . With such implementation, visible light receiver  403  may be strategically positioned where modulated visible light wave signals can be more readily received. Headset  415  can employ any number of standard radio technologies to communicate with the wireless controller  417 ; for example, headset  415  can be Bluetooth enabled. 
     Audio interface  411 , keyboard  419 , display unit  421 , and memory  423  enable a user to interface with mobile station  400 . Display unit  421  can visually display, while audio interface  411  can aurally present, spatial positioning information, as well as other mobile station functions to users. It is noted that audio interface  411  may also be configured with voice recognition technology, such as for permitting users to verbally request mobile station  400  to acquire spatial positioning information via light communication. Memory  423  may be utilized to store various data including user profile information, such as a name, contact information, medical information, positioning information, etc. The user profile information may also be utilized by location module  401  in conjunction with the spatial positioning information to generate an emergency alert notification, which may further define needs for emergency response aids. Radio circuitry  425  permits communication over a radio network using radio frequency (RF) signaling. The radio network may provide a transmission medium for transmitting emergency alert notifications to an emergency response system and/or emergency response personnel. 
       FIG. 5  is a high level flowchart of exemplified mobile station operation in which positioning information is derived and presented to a user of the mobile station. At step  501 , mobile station  400  receives modulated light wave signals, such as modulated visible light wave signals, corresponding to positioning information from, for example, light sources  101  and  103 . Detector  405  of light receiver  403  detects the modulated visible light wave signals. In step  503 , the received modulated light signal is converted into a data signal. The signal may be amplified and filtered in a known manner. At step  505 , the data signal is demodulated via demodulator  407  and processed into positioning data via processor  409 . The positioning data may be ported into location module  401  so that location module  401  may determine spatial positioning information corresponding to the spatial position of mobile station  400 , per step  507 . In step  509 , mobile station  400  presents, via display unit  421 , the spatial positioning information to a user of mobile station  400 . Alternatively or additionally, the spatial positioning information may be conveyed to the user via audio interface  411  and/or headset  415 . 
       FIG. 6  is an exemplary illustration of positioning information displayed at mobile phone  601 . The mobile phone  601  includes display  603 , keyboard  605 , input interface  607 , audio interface  609 , audio output  611 , and light receiver (or detector)  613 . A user may input control commands into the mobile phone via keyboard  605  and/or input interface  607  to acquire positioning information by way of modulated light wave signals received at (or detected by) light receiver  613 . Voice recognition technology may be provided via audio interface  609 , whereby the phone is responsive to uttered voice commands. 
     An example of spatial positioning information that may be presented on display screen  603 , as illustrated at  615 . The display includes general location information  617 , as well as specific coordinate location information  619 . General location information  615  is exemplified as a name of a building, an address of the building, and a floor of the building where mobile phone  601 , i.e., the user of mobile phone  601 , is located. A more detailed description, such as the specific area of the floor at which the light source is positioned, may also be displayed. Specific coordinate information  619  is exemplified by identification of latitude, longitude, and altitude of the mobile phone&#39;s light source. Spatial positioning information may also be presented via speaker  611 . As previously mentioned, a headset (not shown) may also be employed to convey the spatial positioning information to the user, as well as be configured to host light receiver  613 . 
     Although not illustrated, additional information, such as user profile information, that may be of interest can be included in the display and in transmission to a remote emergency response system. For example, the health history of the user may provide essential information to a response team for applying appropriate medical treatment. 
       FIG. 7  is a block diagram of the exemplified system  700  for providing emergency alert notifications including spatial positioning information. Environment  701  may comprise an indoor or otherwise obstructed environment location, such as illustrated in  FIG. 1 . Included therein are one or more fixed LED beacons  703 . LED beacons  703  are light sources, such as light sources  101  and  103 , illustrated in  FIG. 1 , which are configured to convey spatial positioning information for receipt by mobile station  705 . According to one embodiment, LED beacons  703  are visible light sources. Mobile station  705  utilizes this received information to generate an emergency alert notification  707  via an internal notification module  709 . 
     A plurality of LED beacons  703  may be dispersed throughout environment  701  in a predetermined mapped arrangement that may optimize their use as general lighting as well as to provide meaningful location information. In indoor settings, the LED beacons may be strategically located, for example, near elevators, staircases, entrance halls, and restrooms. LED beacons  703  may be “piggy-backed” onto existing infrastructures such as smoke detector systems, alarm systems, emergency door systems, wherein they may be activated in the case of an emergency. In outdoor settings, the LED beacons may be located, for example, at lamp posts, traffic lights, display signs, and the like. 
     Emergency alert notifications  707  may be transmitted to an emergency response system  711  and/or emergency response personnel via one or more communication networks  713 , which may include any wired and/or wireless local area network (LAN), metropolitan area network (MAN), wide-area network (WAN), or any other suitable communication network, or combination thereof. Communication networks  713  may employ various wireless transmission technologies including, for example, CDMA, EDGE, GPRS, GSM, UMTS, WiMAX, WiFi, satellite, and the like. Communication networks  713  may embody or interface with the PSTN, the Internet, or a proprietary network of a service provider, such as a network of an emergency response provider. 
     Emergency response system  711  may comprise computing hardware for receiving emergency alert notifications  707 . For instance, emergency response system  711  may be a computing device of an emergency dispatch operator who may, in turn, convey the information obtained via emergency alert notification  707  to better instruct emergency response personnel. 
       FIGS. 8A-8C  are flowcharts of processes for providing emergency alert notifications, according to various exemplary embodiments. For illustrative purposes, processes  800 ,  830 , and  860  are described with reference to  FIG. 7 .  FIG. 8A  is a flowchart of a process for transmitting, in the event of an emergency, positioning information via modulated light wave signals, according to an exemplary embodiment. At step  801 , LED beacons  703  transmit modulated light wave signals associated with positioning information to a receiving station, such as by the process of  FIG. 3 . The receiving station can then formulate and transmit an emergency alert notification. According to one embodiment, LED beacons  703  unconditionally transmit the modulated light wave signals for reception by the receiving station, e.g., mobile station  705 . In other embodiments, LED beacons  703  transmit the modulated light wave signals upon reception of an indication of an emergency situation. The indication may be received from one or more of the aforementioned existing infrastructures of environment  701 , such as the smoke detector system, etc. 
       FIG. 8B  is a flowchart of a process for transmitting an emergency alert notification in the event of an emergency, according to an exemplary embodiment. At step,  831 , mobile station  705  receives modulated light from one or more light sources, e.g., LED beacons  703 . At step  833 , mobile station  705  determines its location in the manner described with respect to  FIG. 5 . Once the positioning information is determined by mobile station  705 , notification module  709  may generate an emergency alert notification  707  based on this information. Emergency alert notification  707  may embody a text message, video message, or other suitable mobile station signal or packetized data information. Emergency alert notification may also be appended with user profile information to facilitate emergency response. An exemplary emergency alert notification is provided in  FIG. 9 . In step  837 , mobile station  705  transmits emergency alert notification  707  to an emergency response system  711  via communication networks  713 . Transmission may be initialized by the user of mobile station  705  or may be automatically initialized via coded information (e.g., command signals) transmitted to mobile station  705  via the modulated light signals provided by LED beacons  703 . 
       FIG. 8C  is a flowchart of an exemplified process for dispatching aid based on the reception of an emergency alert notification. At step  861 , emergency response system  711  receives an emergency alert notification  707  that includes at least spatial positioning information of a light source at or near mobile station  705 . Emergency alert notification  707  may also include user profile information. Emergency response system  711  may comprise computing hardware of an emergency response dispatch operator. A dispatcher may utilize the information provided by emergency alert notification  707  to provision aid. In step  863 , the dispatcher may attempt to contact the user of mobile station  705  based on a directory address of mobile station  705  provided by emergency alert notification  707 . If the dispatcher does attempt to contact the user, then, per step  865 , the dispatcher can determine whether the user is available for communication. Assuming the user is available for communication then the dispatcher may question the user to determine the user&#39;s condition and whether an emergency response team must be dispatched at or near the location provided by emergency alert notification  707 . If the dispatcher does not contact the user, the user is not available, the user is not “ok”, or help is required, then the dispatcher may dispatch aid based on the information provided via emergency alert notification  707 , per step  869 . If contact is made with the user, the dispatcher can determine if a false alarm/notification has been received. 
       FIG. 9  is an illustration of an exemplary emergency alert notification display that includes positioning information as well as other significant information. As shown, the notification display includes basic contact information  901 , corresponding to the user whose station originated the alert, as well as a date and time stamp  903 . User profile information portion  909  may include any critical information that may be useful during emergency situations. By way of example, the user&#39;s age, blood type, race, prescription allergies, medical history, and the like are shown. General location information portion  905  identifies the name of the building in which the mobile station is situated, the address of the building, and the floor location of the mobile station in the building. Portion  907  lists specific coordinate information, shown as latitude, longitude, and altitude of the light source that has transmitted signals to the mobile station. 
     In this disclosure there are shown and described preferred embodiments of the invention and a few examples of its versatility. It is to be understood that the invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.