EP0782117A1 - Wireless network for controlling various household units - Google Patents

Abstract

Disclosed herein is a local area network for the control of household units, such as appliances and consumer electronics. Each appliance is provided with a transceiver and an interface unit for configuring its household unit in response to command from a network manager. Communications between the network manager and interface units are performed over RF links.

Description

BACKGROUND OF THE INVENTION
• The invention relates in general to wireless communication systems and in particular to wireless local area networks. The concept of networking is evolving from wired networks to wireless networks. In a wired network, a signal flows from one device to another across a physical medium such as a copper wire or a fiber optic. In a wireless network, a signal flows over the airwaves at a radio frequency. The wireless network eliminates two unbecoming aspects of wired networks: the unsightliness of cables, and the expense of cable installation. The wireless network also allows devices in a wireless network to be untethered and moved about freely.
SUMMARY OF THE INVENTION
• The present invention takes advantage of the untethered devices and adapts a wireless network to control a plurality of household units. The network comprises a plurality of interface units corresponding to the plurality of household units, each interface unit being electrically interfaced to a corresponding household unit; and a plurality of first RF transceivers corresponding to the plurality of interface units, each RF transceiver being in electrical communication with a corresponding interface unit. The network further comprises a second RF transceiver operable to communicate with the plurality of first RF transceivers; and a processor programmed to generate commands for controlling and checking the status of the household units. The commands are transmitted to the plurality of interface units by the second transceiver. The interface units configure their corresponding household units in response to the commands.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1 is a block diagram of a wireless network in accordance with the present invention;
• FIG. 2 is a flow chart of the steps performed by a communication device, which forms a part of the network shown in FIG. 1;and
• FIG. 3 is a flowchart of the steps performed by a network manager, which also forms a part of the network shown in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
• FIG.1 shows a local area network 10 including anetwork manager 12 and a number ofhousehold units 14 such as appliances and consumer electronics. Eachhousehold unit 14 is equipped with acommunication device 16 for communicating with thenetwork manager 12 over the airwaves at radio frequencies. On a downlink frequency, thenetwork manager 12 sends status and command frames to thehousehold units 14. Periodically, thenetwork manager 12 transmits status frames for the purpose of assessing the functional status of thehousehold Kits 14. Occasionally, thenetwork manager 12 transmits command frames for the purpose of programming aparticular household unit 14. On an uplink frequency, thehousehold units 14 transmit bursts to thenetwork manager 12 in response to the status and command frames. The bursts indicate the functional status of thehousehold units 14.
• Eachcommunication device 16 includes afirst transceiver 18 anddevice driver 20. Thefirst transceiver 18 receives a frame on the downlink frequency and supplies the received frame to thedevice driver 20. Thefirst transceiver 18 can be a simple ASIC that has low input power, usually on the order of several milliwatts. The range varies, typically up to a few hundred feet. Thedevice driver 20 is a programmable logic device that is adapted to accept data from the electronics of thehousehold unit 14. Both thefirst transceiver 18 and thedevice driver 20 draw current from the household unit's power supply. Operation of thecommunication device 16 is described below in connection with FIG. 2.
• Thenetwork manager 12 includes apersonal computer 22 having amicroprocessor 24, a storage device such as ahard disk drive 26, adisplay 28 and akeyboard 30. Thenetwork manager 12 also includes anexpansion board 32. Theexpansion board 32 is electrically connected to themicroprocessor 24 and includes asecond transceiver 34 that communicates with all of thefirst transceivers 18 of thecommunication devices 16. Theexpansion board 32 also includes adevice driver 36 that interfaces thesecond transceiver 34 with themicroprocessor 24.
• By way of example, thehousehold units 14 include a television set, a VCR, a water heater, a thermostat for the air conditioner, a security system, and an oven. Thenetwork manager 12 transmits a status frame to check the functionality of theunits 14. The frame is received simultaneously by the television set, VCR, water heater, thermostat, security system, and oven. The television set, oven and security system respond with bursts indicating whether they are turned on or off. The water heater and thermostat respond with bursts indicating the temperatures at which they are set. The VCR responds with a burst indicating the time and programs it is set to record.
• Thenetwork manager 12, which stores the desired settings for thehousehold units 14, compares the status contained in each burst to the desired setting. If the television is turned on, but the desired setting indicates that it should be turned off, thenetwork manager 12 transmits a command frame to the television set, commanding it to turn off. If the temperature of the room is cooler than it should be, the network manager sends another frame commanding the thermostat to turn off the air conditioner. If the VCR is programmed to record "The Simpsons", thenetwork manager 12 sends yet another command frame commanding the VCR to turn off. FIG. 2 shows the steps performed by acommunication device 16 for ahousehold unit 14. Thefirst transceiver 18 receives a frame (step 102), and thedevice driver 20 separates the frame into a header portion and a data portion (step 104). The header portion indicates whichhousehold unit 14 the frame is intended for. If the address in the header portion matches the address of the household unit 14 (step 106), thedevice driver 20 processes the data portion (step 108). If the data portion indicates that the frame is a status frame (step 110), thedevice driver 20 generates a burst indicating source and status (e.g., thermostat and room temperature setting) (step 112), and commands thefirst transceiver 18 to send the burst on the uplink frequency (step 114). If the data portion indicates that the frame is a command frame (step 110), thedevice driver 20 sets thehousehold unit 14 to the setting stored in the data portion (step 116), generates a burst indicating the source and the new status of the household unit 14 (step 118) and commands thefirst transceiver 18 to send the burst on the uplink frequency (step 114).
• FIG. 3 shows the steps performed by thenetwork manager 12. Thenetwork manager 12 executes an application program stored on thehard disk drive 26. When the program begins, a menu is displayed on the display 28 (step 202). The menu specifies certain states, such as "AT HOME," "ASLEEP" and "ON VACATION." The menu also specifies the settings at the various states for thehousehold units 14. Each state has its own default settings. The default settings can also be stored on the computerhard drive 26.
• The user selects the state and reviews the settings that are displayed. If the user wishes to change the settings (step 204), an input is made via thekeyboard 30. The new setting is received (step 206) and the settings on the menu are updated (step 202). Once satisfied with the settings, the user can either exit the program (steps 208 and 210) or allow thenetwork manager 12 to control thehousehold units 14. When thenetwork manager 12 begins control, it sends a status frame to the household units 14 (step 212) and awaits the return bursts (step 216).
• Once the bursts are received (step 218), each status therein is compared to a desired setting (step 220). For eachhousehold unit 14, if the status indicated in the burst matches the desired setting (step 222), thenetwork manager 12 waits an interval and then sends the next status frame (step 224).
• If the status indicated in a burst does not match the desired setting (step 222), thenetwork manager 12 sends a command frame commanding thehousehold unit 14 to change its setting (step 226). After the command frame is transmitted, thenetwork manager 12 awaits a return burst indicating the new status of the unit 14 (step 228).
• Returning to FIG. 1, if the computer is equipped with a modem 38, thenetwork manager 12 can be connected to a wide area network. The wide area network provides access to other local area networks within a neighbourhood. It also provides a connection to the local police station. Thenetwork manager 12 can call the police station if the security system indicates an unauthorized entry through a window or door. Certainty of a break-in is increased if ahousehold unit 14 does not respond to a status frame.
• Thus disclosed is a network 10 for the control ofhousehold units 14. Thehousehold units 14 can be checked for status and they can be programmed remotely. Additionally, all of theunits 14 in the household can be programmed conveniently from a single source. The network 10 can also function as a home security system, providing a high level of security and reliability.
• It is understood that the embodiments described herein are merely exemplary and that many modifications and variations of the present invention are possible in light of the above teachings. For example, the network 10 can be used to control various units in an office complex as well as in a home. Therefore, the scope of the present invention is limited only by the appended claims.

Claims (1)

1. A local area network (10) for a plurality of household units (14), comprising:

   a plurality of interface units (20) corresponding to the plurality of household units (14), each interface unit being electrically interfaced to a corresponding household unit;

   a plurality of first RF transceivers (18) corresponding to the plurality of interface units (20), each RF transceiver being in electrical communication with a corresponding interface unit;

   a second RF transceiver (34) operable to communicate with the plurality of first RF transceivers (18);

   and a processor (24) programmed to generate commands for controlling and checking the status of the household units, the commands being transmitted to the plurality of interface units by the second transceiver, the interface units configuring their corresponding household units in response to the commands.

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