Abstract: Optical networks as defined by the IEEE 802.3ah standard suffer from Stimulated Raman Scattering (SRS) that causes data transmission at a first optical wavelength to interfere with broadcast video transmission at a second optical wavelength in single mode optical fibers. The problem is exacerbated when data is not being transmitted across the network; and instead, an idle pattern transmission is being transmitted in order to keep the network synchronized. The repetitive nature of the idle pattern transmission leads to the SRS optical interference effect. This optical interference effect is mitigated when countermeasures are implemented to modify the idle pattern transmissions or to transmit random data in place of the idle pattern transmissions.

Abstract: An optical network can include a data service hub, a laser transceiver node, and a subscriber optical interface. The data service hub can comprise a satellite antenna and a RF receiver for receiving satellite TV-band electrical signals. These electrical signals can be converted into the optical domain and then propagated over the optical network through optical waveguides to the subscriber optical interface. The subscriber optical interface can comprise an optical filter and a satellite analog optical receiver. The optical filter can separate the satellite TV-band optical signals having a first optical wavelength from other optical signals such as cable TV-band optical signals with a second optical wavelength and data optical signals with a third optical wavelength. The satellite analog optical receiver can further comprise various mechanisms for controlling access to the satellite TV-band signals.

Abstract: An optical fiber network can include an outdoor laser transceiver node that can be positioned in close proximity to the subscribers of an optical fiber network. The outdoor laser transceiver node does not require active cooling and heating devices that control the temperature surrounding the laser transceiver node. The laser transceiver node can adjust a subscriber's bandwidth on a subscription basis or on an as-needed basis. The laser transceiver node can also offer data bandwidth to the subscriber in preassigned increments. Additionally, the laser transceiver node lends itself to efficient upgrading that can be performed entirely on the network side. The laser transceiver node can also provide high speed symmetrical data transmission. Further, the laser transceiver node can utilize off-the-shelf hardware to generate optical signals such as Fabry-Perot (F-P) laser transmitters, distributed feed back lasers (DFB), or vertical cavity surface emitting lasers (VCSELs).

Abstract: An enclosure for facilitating and protecting splices or connections between communication transmission mediums can include a housing having a first port and a drop port. The first port can allow a distribution cable containing a transmission medium to enter the housing. The drop port can allow another transmission medium to enter the housing, and it can allow a transmission medium to be added or removed without disturbing existing transmission mediums or connections in the housing. A drop plug can be provided to seal the drop port. The enclosure can also include a cover plate having a gasket coupled to its perimeter and being removable with the cover plate. Strain relief for the transmission mediums entering the enclosure can also be provided. Two-stage strain relief and single-stage strain relief can be provided for the transmission mediums entering through the first port and the drop port, respectively.

Abstract: A return path system includes inserting RF packets between regular upstream data packets, where the data packets are generated by communication devices such as a computer or internet telephone. The RF packets can be derived from analog RF signals that are produced by legacy video service terminals. At a data service hub, a digitized-RF-to-packet converter (DRPC) can convert the RF packets into standard sized packets such as Ethernet packets for processing by a video services controller. In this way, the present invention can provide an RF return path for legacy terminals that shares a return path for regular data packets in an optical network architecture.

Abstract: An optical fiber network can include an outdoor laser transceiver node that can be positioned in close proximity to the subscribers of an optical fiber network. The outdoor laser transceiver node does not require active cooling and heating devices that control the temperature surrounding the laser transceiver node. The laser transceiver node can adjust a subscriber's bandwidth on a subscription basis or on an as-needed basis. The laser transceiver node can also offer data bandwidth to the subscriber in preassigned increments. Additionally, the laser transceiver node lends itself to efficient upgrading that can be performed entirely on the network side. The laser transceiver node can also provide high speed symmetrical data transmission. Further, the laser transceiver node can utilize off-the-shelf hardware to generate optical signals such as Fabry-Perot (F-P) laser transmitters, distributed feed back lasers (DFB), or vertical cavity surface emitting lasers (VCSELs).

Abstract: Forming a plurality of loops in an optical fiber around a spool adjacent to an exposed end face can suppress internal reflections from the exposed end face. The radius of the loops can attenuate light that is propagating to and from the end face by causing light to leak out of the optical fiber's core and into its cladding. The radius can be selected to control physical stress in the optical fiber and promote reliability. The radius and the number of loops can be selected to meet a return loss specification. The loops can be formed by coiling the optical fiber around a spool that includes a slot for holding the optical fiber until it is put into service.

Abstract: An optical receiver circuit receives analog optical signals and outputs corresponding electrical signals. The circuit's amplifier can amplify a modulated signal from a photodiode. Gain control can adjust the amplifier's gain to compensate for power fluctuation in the optical signals. Linear compensation can enhance the linearity of the gain adjustment in response to optical power fluctuation and can facilitate feedforward gain control. A digital controller can implement the linear compensation. The circuit can operate with an impedance mismatch in the coupling between the photodiode and the amplifier, thereby avoiding the need for an impedance matching transformer in that coupling.

Abstract: An enclosure for facilitating and protecting splices or connections between communication transmission mediums can include a housing having a first port and a drop port. The first port can allow a distribution cable containing a transmission medium to enter the housing. The drop port can allow another transmission medium to enter the housing, and it can allow a transmission medium to be added or removed without disturbing existing transmission mediums or connections in the housing. A drop plug can be provided to seal the drop port. The enclosure can also include a cover plate having a gasket coupled to its perimeter and being removable with the cover plate. Strain relief for the transmission mediums entering the enclosure can also be provided. Two-stage strain relief and single-stage strain relief can be provided for the transmission mediums entering through the first port and the drop port, respectively.

Abstract: Analog video signals are communicated from multiple service providers to subscribers by using analcg optical carriers. Unlike digital optical carriers that typically support data services or IP TV, analog optical carriers that can be demodulated or translated back into the analog radio-frequency (RF) signals do not require additional and costly hardware for reception by a RF receiving device such as a television (TV) set. With the present invention, a TV set does not need significant digital hardware such as a digital set top box to allow the TV set to view video signals from a desired service provider. The present invention can allow a plurality of competing service providers to offer video services to a subscriber through a single optical network.

Abstract: A system and method for tuning a broadcast receiver such as a television set with a subscriber optical interface (SOI) that can be located outside a subscriber's premises and can be adjacent to the subscriber's premises. For example, a subscriber optical interface can be mounted on a side of a home which converts optical data and optical video signals received from an optical waveguide to electrical signals. Because of the hardware contained in the subscriber optical interface, any video processing hardware that is present within the subscriber's premises for tuning video programs can be reduced or substantially eliminated without sacrificing a range of services available to a subscriber from a fiber-to-the-home optical network.

Abstract: An optical transmitter of a subscriber optical interface and an optical receiver of a laser transceiver node can be designed to a frequency of data that is formatted according to a predetermined network protocol, that is encoded with a predetermined coding scheme, and that is transmitted according to a predetermined data transmit timing scheme. The frequency of data is an occupied frequency of a protocol when the data comprises a maximum number of like bits permitted by the protocol. An optical transmitter and optical receiver can be designed to a lowest occupied frequency of data that is encoded with 8B/10B encoding, and that is propagated upstream according to time division multiple access (TDMA). In this way, upstream optical communications can be maximized for speed.

Abstract: An enclosure for facilitating and protecting splices or connections between communication transmission mediums can include a housing having a first port and a drop port. The first port can allow a distribution cable containing a transmission medium to enter the housing. The drop port can allow another transmission medium to enter the housing, and it can allow a transmission medium to be added or removed without disturbing existing transmission mediums or connections in the housing. A drop plug can be provided to seal the drop port. The enclosure can also include a cover plate having a gasket coupled to its perimeter and being removable with the cover plate. Strain relief for the transmission mediums entering the enclosure can also be provided. Two-stage strain relief and single-stage strain relief can be provided for the transmission mediums entering through the first port and the drop port, respectively.

Abstract: An optical transmitter of a subscriber optical interface and an optical receiver of a laser transceiver node can be designed to a frequency of data that is formatted according to a predetermined network protocol, that is encoded with a predetermined coding scheme, and that is transmitted according to a predetermined data transmit timing scheme. The frequency of data is an occupied frequency of a protocol when the data comprises a maximum number of like bits permitted by the protocol. An optical transmitter and optical receiver can be designed to a lowest occupied frequency of data that is encoded with 8B/10B encoding, and that is propagated upstream according to time division multiple access (TDMA). In this way, upstream optical communications can be maximized for speed.

Abstract: A return path may include a modem pair that is coupled to existing electrical waveguides in a structure such as a house or office building. Specifically, a first modem of the modem pair may be coupled to a first end of a coaxial cable and to a video service terminal. A second modem of the modem pair may be coupled to a second end of the coaxial cable and a data interface. The first modem can modulate video control return packets onto an RF carrier that is propagated over the coaxial cable to the second modem. The video control return packets can be formatted as Ethernet type packets. The second modem can demodulate the RF carrier to extract the video control return packets and to forward these packets towards a data service hub.

Abstract: Unlike the conventional art which polices data at the entry points of a network, a transceiver node can police or monitor downstream bandwidths for quality of service at exit portions of an optical network. That is, the transceiver node can police downstream communication traffic near the outer edges of an optical network that are physically close to the subscribers of the optical network. In this way, a network provider can control the volume or content (or both) of downstream communications that are received by subscribers of the optical network. In addition to controlling the volume of communications that can be received by a subscriber, the transceiver node employs a plurality of priority assignment values for communication traffic. Some priority assignment values are part of a weighted random early discard algorithm that enables an output buffer to determine whether to drop data packets that are destined for a particular subscriber.

Abstract: A system and method establishes a secure communication channel over an optical network. More specifically, the system and method can generally include securing a communications channel to prevent unauthorized access such as eavesdropping or masquerading by employing 1) an encryption scheme derived from the non-linear filtering of shift registers, 2) a method for authenticating and exchanging parameters between two parties over an unsecured data channel for deriving a shared encryption key having a property of perfect forward secrecy, and 3) employing a unique format of the messages that can transport non-secret key exchange parameters over an unsecured data channel and secure communications over a data channel.

Abstract: A protocol for an optical network can control the time at which subscriber optical interfaces of an optical network are permitted to transmit data to a transceiver node. The protocol can prevent collisions of upstream transmissions between the subscriber optical interfaces of a particular subscriber group. With the protocol, a transceiver node close to the subscriber can allocate additional or reduced upstream bandwidth based upon the demand of one or more subscribers. That is, a transceiver node close to a subscriber can monitor (or police) and adjust a subscriber's upstream bandwidth on a subscription basis or on an as-needed basis. The protocol can account for aggregates of packets rather than individual packets. By performing calculation on aggregates of packets, the algorithm can execute less frequently which, in turn, permits its implementation in lower performance and lower cost devices, such as software executing in a general purpose microprocessor.

Abstract: A return path system includes inserting RF packets between regular upstream data packets, where the data packets are generated by communication devices such as a computer or internet telephone. The RF packets can be derived from analog RF signals that are produced by legacy video service terminals. In this way, the present invention can provide an RF return path for legacy terminals that shares a return path for regular data packets in an optical network architecture. The invention operates independently of a legacy upstream transmission timing scheme so that the legacy upstream transmission timing scheme can remain effective in preventing data collisions. In other embodiments, the present invention allows for less complex hardware for subscribers that are not taking data services. Further, an optical signal present line in combination with a driver may be employed in order to reduce the amount of hardware in a laser transceiver node.

Abstract: The present invention is generally drawn to optical network architecture that can include a multi-subscriber optical interface that can service a plurality of subscribers that are located in close proximity relative to one another. For example, the multi-subscriber optical interface can service multiple dwelling units such as an apartment complex that has many different subscribers to the optical network system. Further, the invention can also service subscribers over the same optical waveguide who may have different bandwidth needs, such as businesses, personal/home users and the like.