Abstract: A Gigabit Ethernet-based passive optical network that can reliably transmit data is disclosed. The network includes an OLT for receiving a public key through a transmission medium, encrypting a secret key by means of the received public key, transmitting the encrypted secret key, encrypting data by means of the secret key, and transmitting the encrypted data, the OLT being located in a service provider-side. The network also includes an ONT for transmitting the public key to the OLT, receiving the secret key transmitted from the OLT, decrypting the secret key by means of a private key, receiving the data, and decrypting the received data by means of the decrypted the secret key. The public key is used for encrypting the secret key. The secret key is encrypted by means of the public key. The data is encrypted by the OLT by means of the secret key.

Abstract: A passive optical network (PON) for providing a large amount of data at high speed to subscribers is provided. In particular, a PON employing a multi-carrier CDMA in which a CDMA method is applied for an upstream signal is provided. The PON employing a multi-carrier CDMA includes: optical network terminals (ONTs) for transmitting CDMA-based data using multiple carriers to an optical line terminal (OLT) and for receiving Ethernet-based data transmitted from the OLT; the OLT for transforming CDMA-based data received from the ONT into Ethernet-based data, for transmitting the Ethernet-based data to a higher network, and for transmitting Ethernet-based date to the ONTs; and an optical coupler for coupling CDMA-based optical signals transmitted from the ONTs, for transmitting the coupled optical signal to the OLT, and for distributing an Ethernet-based optical signal transmitted from the OLT to the ONTs.

Abstract: A wideband erbium-doped optical fiber amplifier is disposed among an optical fiber through which a first and second band-band optical signals (for example, the C-band and L-band) are transmitted and forms a first optical path and a second optical path parallel to each other. The wideband erbium-doped optical fiber amplifier comprising a first amplifying section disposed on the first optical path, including a first erbium-doped optical fiber to amplify the first-band optical signals, a filter to gain-flatten the amplified first-band optical signals, wherein a reflected portion of the first band optical signal by the filter is directed to the second optical path; and a second amplifying section disposed on the second optical path, having a second erbium-doped optical fiber to amplify received second-band optical signals, wherein the reflected first-band optical signal is used to pump the second erbium-doped optical fiber.

Abstract: A bidirectional WDM self-healing ring network is provided and includes an outer ring network and an inner network for processing N units of optical signals and for performing a protection switching by using the outer ring network when the inner ring network suffers a link failure.

Abstract: A Gigabit Ethernet passive optical network (GE-PON) and method for accurately detecting an error of data to securely transmit the data.

Abstract: A Gigabit Ethernet passive optical network (GE-PON) for securely transferring data through exchange of an encryption key comprises an optical line terminal (OLT) for encrypting a secret key using a public key received through a transmission medium, transmitting the encrypted secret key, encrypting data using the encrypted secret key, and transmitting the encrypted data, and at least one optical network terminal (ONT) for transmitting the public key to the OLT, decrypting the encrypted secret key transmitted from the OLT using a private key, and decrypting the data encrypted with the encrypted secret key, transmitted from the OLT, using the decrypted secret key.

Abstract: A Gigabit Ethernet-based passive optical network that can reliably transmit data is disclosed. The network includes an OLT for receiving a public key through a transmission medium, encrypting a secret key by means of the received public key, transmitting the encrypted secret key, encrypting data by means of the secret key, and transmitting the encrypted data, the OLT being located in a service provider-side. The network also includes an ONT for transmitting the public key to the OLT, receiving the secret key transmitted from the OLT, decrypting the secret key by means of a private key, receiving the data, and decrypting the received data by means of the decrypted the secret key. The public key is used for encrypting the secret key. The secret key is encrypted by means of the public key. The data is encrypted by the OLT by means of the secret key.

Abstract: A wideband erbium-doped optical fiber amplifier is disposed among an optical fiber through which a first and second band-band optical signals (for example, the C-band and L-band) are transmitted and forms a first optical path and a second optical path parallel to each other. The wideband erbium-doped optical fiber amplifier comprising a first amplifying section disposed on the first optical path, including a first erbium-doped optical fiber to amplify the first-band optical signals, a filter to gain-flatten the amplified first-band optical signals, wherein a reflected portion of the first band optical signal by the filter is directed to the second optical path; and a second amplifying section disposed on the second optical path, having a second erbium-doped optical fiber to amplify received second-band optical signals, wherein the reflected first-band optical signal is used to pump the second erbium-doped optical fiber.

Abstract: A passive optical network (PON) for providing a large amount of data at high speed to subscribers is provided. In particular, a PON employing a multi-carrier CDMA in which a CDMA method is applied for an upstream signal is provided. The PON employing a multi-carrier CDMA includes: optical network terminals (ONTs) for transmitting CDMA-based data using multiple carriers to an optical line terminal (OLT) and for receiving Ethernet-based data transmitted from the OLT; the OLT for transforming CDMA-based data received from the ONT into Ethernet-based data, for transmitting the Ethernet-based data to a higher network, and for transmitting Ethernet-based date to the ONTs; and an optical coupler for coupling CDMA-based optical signals transmitted from the ONTs, for transmitting the coupled optical signal to the OLT, and for distributing an Ethernet-based optical signal transmitted from the OLT to the ONTs.

Abstract: A bidirectional WDM self-healing ring network is provided and includes an outer ring network and an inner network for processing N units of optical signals and for performing a protection switching by using the outer ring network when the inner ring network suffers a link failure.