Abstract: A method and apparatus for providing a local IP access service to a User Equipment (UE) attached to a femtocell including a Packet Data Network (PDN) gateway function in a wireless communication system. A method includes receiving a service request from a User Equipment (UE), transmitting an initial UE message including information on a local gateway to a Mobility Management Entity (MME), storing bearer information carried in an initial context setup request transmitted by the MME, receiving a Packet Data Network (PDN) connectivity request from the UE, forwarding the PDN connectivity request to the MME, receiving a create session request from the MME, and establishing a radio bearer with the local gateway, the local gateway being co-located with the femtocell.

Abstract: An air conditioner includes a plurality of compressors, a plurality of oil separators, a plurality of oil collection pipes, a common inlet pipe, and a plurality of branch inlet pipes. The oil separators are connected to outlets of the compressors for separating a refrigerant and/or oil discharged from the compressors. The oil collection pipes are respectively connected to the oil separators for collecting oil separated by the oil separators. The common inlet pipe receives the collected oil and allows the oil to flow to the compressors. The branch inlet pipes branch off from the common inlet pipe and are respectively connected to the compressors.

Abstract: A method for controlling a multi-unit air conditioning system adapted to cool or heat room spaces while passing a refrigerant in one direction or in a reverse direction is disclosed. In the method, which is applied to a multi-unit air conditioning system including at least three compressors, when a compressor re-operation is repeatedly carried out after all of the compressors have been turned off, to turn on again at least one of the compressors, repetition of the compressor re-operation is carried out for a predetermined number of different orders in such a manner that at least one of the compressors is turned on first in an associated order of the repeated compressor re-operation.

Abstract: A supercooling apparatus of a simultaneous cooling and heating type multiple air conditioner comprises a liquid pipe header connected to outdoor heat exchangers, a plurality of branch liquid pipes branched from the liquid pipe header and connected to a plurality of indoor heat exchangers, respectively, and a supercooling mechanism mounted at least one of the branch liquid pipes for cooling refrigerant flowing to the indoor heat exchangers. The liquid refrigerant discharged from the heating-side indoor heat exchangers is supercooled by supercooling heat exchangers, and is then introduced into the cooling-side indoor heat exchangers. Consequently, noise generated from the cooling-side heat exchangers during the simultaneous cooling and heating operation is reduced, and cooling capacity of the multi air conditioner is improved.

Abstract: Multi-type air conditioner comprising an outdoor unit installed in an outdoor, comprising a compressor, a refrigerant flow controlling part connected to a discharge end of the compressor for guiding the refrigerant proper to operation conditions selectively, an outdoor heat exchanger connected to the refrigerant flow controlling part, a defrosting device at a side of the outdoor heat exchanger, and a piping system connected between the parts, a plurality of indoor units each installed in a room and having an indoor heat exchanger and an electronic expansion valve having one end connected to one end of the indoor heat exchanger, and a distributor between the outdoor unit and the indoor units for selectively guiding refrigerant from the outdoor unit to the plurality of indoor units proper to operation conditions, and guiding the refrigerant passed through the indoor units to the outdoor unit again.

Abstract: An air conditioner having a service valve assembly which comprises a connection body connected with a refrigerant pipe through which a refrigerant flows, and having a penetration passage through which the refrigerant flows; an opening/closing unit disposed in the connection body, and having a blocking hole for opening/closing the passage of the refrigerant flowing through the penetration passage; a plurality of ports disposed at the connection body, respectively, by a particular interval therebetween, connected with the penetration passage, and having an opened end portion, respectively; and a filter unit removably coupled to each end portion of the ports such that the refrigerant flowing through the penetration passage is bypassed to the ports to thus be filtered thereby, whereby it is possible to basically solve the problem in a blocking caused by moisture and foreign materials within a circulation system of the air conditioner, and to simplify the construction of the system by being provided with a filter

Abstract: Provided is an air conditioner, particularly, an apparatus and method for controlling a super-heating degree in a heat pump system for preventing a liquid refrigerant from flowing into a compressor. The method includes: operating the heat pump system; receiving a present outdoor temperature, a pipe absorption temperature and a low pressure value of a compressor, respectively; computing a present absorption super-heating degree from a difference between the absorption temperature of the compressor and a saturated temperature at a low pressure side; and comparing an targeted absorption super-heating degree set in advance, with the computed present absorption super-heating degree according to the received outdoor temperature, and controlling the system so that the present absorption super-heating degree may follow the targeted absorption super-heating degree.

Abstract: Disclosed is an apparatus and method for preventing liquid refrigerant accumulation in an accumulator of an outdoor unit of an air conditioner. The method includes the steps of: determining a state of a compressor; if the compressor is in standby mode or off state, turning on a four-way valve; determining whether the state of the compressor in standby mode or off state continues longer than a predetermined amount of time; and if the state of the compressor continues longer than the predetermined amount of time, closing an expansion valve. Particularly, high-pressure refrigerant flows in the closed expansion valve while low-pressure refrigerant flows in a check valve through the four-way valve.

Abstract: An air conditioner includes a plurality of compressors, a plurality of oil separators, a plurality of oil collection pipes, a common inlet pipe, and a plurality of branch inlet pipes. The oil separators are connected to outlets of the compressors for separating a refrigerant and/or oil discharged from the compressors. The oil collection pipes are respectively connected to the oil separators for collecting oil separated by the oil separators. The common inlet pipe receives the collected oil and allows the oil to flow to the compressors. The branch inlet pipes branch off from the common inlet pipe and are respectively connected to the compressors.

Abstract: Disclosed is a method for controlling an air conditioner. In particular, driving modes of elements, namely sucking/discharge compressure, of the compressor in operation are determined so that variable means are controlled to ensure for the elements of the compressor to be within predetermined value ranges in safe area. According to the present invention, vibrations/noises that usually occur when the compressor is in unstable area are greatly reduced and thus, the compressor can be protected from damages.

Abstract: A system for controlling an air conditioner includes a plurality of outdoor units each having at least one compressor and an outdoor heat exchanger, an indoor unit connected to the outdoor units by a refrigerant tube, the indoor unit having an indoor heat exchanger, and a pressure regulating tube for equalizing pressure according to an operation mode. The pressure regulating tube is connected between the outdoor units.

Abstract: An air conditioner including a plurality of compressors uses at least one oil separator for separating oil from an oil-mixed refrigerant discharged from the compressors. The air conditioner performs an oil balancing operation, during which some compressors operate and some do not. At least a portion of the oil separated by the oil separator is distributed to the compressors that are not operating during the oil balancing operation.

Abstract: Multi-type air conditioner comprising an outdoor unit installed in an outdoor, comprising a compressor, a refrigerant flow controlling part connected to a discharge end of the compressor for guiding the refrigerant proper to operation conditions selectively, an outdoor heat exchanger connected to the refrigerant flow controlling part, a defrosting device at a side of the outdoor heat exchanger, and a piping system connected between the parts, a plurality of indoor units each installed in a room and having an indoor heat exchanger and an electronic expansion valve having one end connected to one end of the indoor heat exchanger, and a distributor between the outdoor unit and the indoor units for selectively guiding refrigerant from the outdoor unit to the plurality of indoor units proper to operation conditions, and guiding the refrigerant passed through the indoor units to the outdoor unit again.

Abstract: Multi-type air conditioner comprising an outdoor unit installed in an outdoor, comprising a compressor, a refrigerant flow controlling part connected to a discharge end of the compressor for guiding the refrigerant proper to operation conditions selectively, an outdoor heat exchanger connected to the refrigerant flow controlling part, a defrosting device at a side of the outdoor heat exchanger, and a piping system connected between the parts, a plurality of indoor units each installed in a room and having an indoor heat exchanger and an electronic expansion valve having one end connected to one end of the indoor heat exchanger, and a distributor between the outdoor unit and the indoor units for selectively guiding refrigerant from the outdoor unit to the plurality of indoor units proper to operation conditions, and guiding the refrigerant passed through the indoor units to the outdoor unit again.

Abstract: Air conditioner, and method for controlling an operation of the same, the air conditioner including a sheath heater in the accumulator for heating the refrigerant in room heating for delaying deposition of frost on the outdoor heat exchanger. The sheath heater includes a coil formed heat generating part, and two electrodes connected to the heat generating part for supplying power. The method including the step of varying the heat generating rate of the sheath heater with an exterior temperature or a capacity of the indoor unit, thereby delaying deposition of frost on the outdoor heat exchanger.

Abstract: Multi-type air conditioner including an outdoor unit installed in an outdoor, including a compressor, a refrigerant flow controlling part connected to a discharge end of the compressor for guiding the refrigerant proper to operation conditions selectively, and an outdoor heat exchanger connected to the refrigerant flow controlling part, a plurality of indoor units each installed in a room and having an indoor heat exchanger and an electronic expansion valve having one end connected to one end of the indoor heat exchanger, a plurality of, at least two, distributors between the outdoor unit and the plurality of indoor units for improving installation freedom of the plurality of indoor units, selectively guiding refrigerant from the outdoor unit to the plurality of indoor units proper to operation conditions, and guiding the refrigerant passed through the indoor units to the outdoor unit again, and a device for shutting off introduction of the refrigerant into the distributors connected to inoperative indoor uni

Abstract: An air conditioner having a service valve assembly which comprises a connection body connected with a refrigerant pipe through which a refrigerant flows, and having a penetration passage through which the refrigerant flows; an opening/closing unit disposed in the connection body, and having a blocking hole for opening/closing the passage of the refrigerant flowing through the penetration passage; a plurality of ports disposed at the connection body, respectively, by a particular interval therebetween, connected with the penetration passage, and having an opened end portion, respectively; and a filter unit removably coupled to each end portion of the ports such that the refrigerant flowing through the penetration passage is bypassed to the ports to thus be filtered thereby, whereby it is possible to basically solve the problem in a blocking caused by moisture and foreign materials within a circulation system of the air conditioner, and to simplify the construction of the system by being provided with a filter

Abstract: An apparatus for testing an air conditioner is disclosed. The apparatus includes a first wireless device connected to the air conditioner, and a second wireless device connected to a test terminal. The first wireless device transmits and receives test result information and test-related information based on a testing program installed in the test terminal in a local-area wireless communication manner, and the second wireless device transmits and receives the test-related information and test result information based on the testing program in the local-area wireless communication manner. Therefore, local-area wireless communication can be carried out between the air conditioner and the test terminal, thereby making it possible to significantly save trouble for installation of testing instruments, such as cables and a converter, and to significantly curtail costs and manpower for test work.

Abstract: Disclosed is a multi-air conditioner in which heating and cooling operations are performed at the same time, the number of connection pipes connecting outdoor unit and distributor is simplified to three to flow a specific pressure and phase refrigerant through each connection pipe regardless of operation condition.