Community Antenna Television Research Articles

Influence of phase-sensitive optical time-domain reflectometer on community antenna television transmission

Multiple studies have been carried out to analyze the mutual interaction of a phase-sensitive optical time-domain reflectometer (Φ-OTDR) and parallel digital data traffic. However, interactions with analog transmission, e.g., community antenna television (CATV), have not been addressed. Our study examines and presents the influence of a developed sensing system Φ-OTDR when operated simultaneously on parallel fibers with the transfer of data from an analog CATV system. Three scenarios are suggested and discussed for the measurements and optimization of the data network in the analog CATV data transfer. These scenarios are suggested to enable the verification of the mutual interactions between data networks with the analog data transfer and suggested sensing system and to determine how the data network with the analog data transfer may or may not be influenced by the sensing system. The optimization and measurements prove that the analog CATV data transfer was negatively influenced by the sensing system Φ-OTDR, and the channel bit error rate increased by nearly half. The implementation of the sensing system Φ-OTDR was realized for a data network, followed by the testing and optimization, which proved that the safe spectral distance between the CATV and the sensing system is 150 GHz and higher.

Bidirectional hybrid OFDM based free-space/wireless-over-fiber transport system

We propose and demonstrate a successful application of orthogonal frequency division multiplexing (OFDM), reflective semiconductor optical amplifier and polarization multiplexing techniques to facilitate bidirectional hybrid OFDM based integrated free-space optics and wireless transport system. The downlink 12 Gbps OFDM data-stream and 79 community antenna television (CATV) channels are transmitted over 50 km single mode fiber (SMF) as well as 12 m and 10 m free-space link, respectively. The uplink 10 Gbps/5 GHz and 5 Gbps/3.5 GHz OFDM data streams are communicated over separate 50 km SMF along with 8 m wireless links. We have used 32-quadrature amplitude modulation (QAM) and 16-QAM modulation formats for downlink and uplink, correspondingly. The performance of the system is observed by evaluating carrier-to-noise ratio (CNR), composite second-order (CSO) and composite-triple-beat (CTB) for the CATV signal, and constellations diagrams, bit error rate (BER), signal-to-noise ratio (SNR), and error vector magnitude (EVM) values for the OFDM signals. After transmission over 50 km SMF as well as 10 m free-space, the resulting CNR, CSO and CTB values are > 51 dB, 23.3 dB, respectively. 4 dBm and 3.2 dBm power penalties at BER of $$10^{ - 8}$$, below 13% EVM and > 21.3 dB/ > 22.2 dB SNR values are observed for the uplink 10 Gbps/5 GHz and the 5 Gbps/3.5 GHz OFDM data signals, respectively, over 50 km SMF as well as 8 m wireless is observed.

Cable Television and the Aereo Case Then and Now

The Supreme Court will soon confront whether Aereo’s service – which affords subscribers access to over-the-air television signals through the use of dime-sized, customer-specific antennas and remote digital video recorders – infringes the Copyright Act’s public performance right. In endorsing the Second Circuit’s decision holding that Aereo does not infringe, some advocates have suggested that such disruptive digital age technology is well beyond what Congress contemplated when it drafted the “Transmit Clause” of the public performance right nearly 50 years ago. Our exploration of the history indicates otherwise.The drafters of the Copyright Act of 1976 had greater foresight than the Second Circuit recognized. As the 1965 Supplementary Report of the Register of Copyrights emphasizes, “it is becoming increasingly apparent that the transmission of works by nonprofit broadcasting, linked computers, and other new media of communication, may soon be among the most important means of disseminating them, and will be capable of reaching vast audiences. Even when these new media are not operated for profit, they may be expected to displace the demand for authors’ works by other users from whom copyright owners derive compensation.” The following year, Congress explained its intent in crafting the public performance right to cover transmissions of performances “whether the members of the public capable of receiving the performance or display receive it in the same place or in separate places and at the same time or at different times.” Its 1966 report notes that liability would arise “whenever the potential recipients of the transmission represent a limited segment of the public, such as...the subscribers of a community antenna television service.” It noted that the “same principles apply...where the transmission is capable of reaching different recipients at different times, as in the case of sounds or images stored in an information system and capable of being performed or displayed at the initiative of individual members of the public” – language that comes eerily close to describing Aereo’s service.It is difficult to imagine the drafters not considering Aereo to fall comfortably within their conception of a public performance right, especially when considered in light of the drafters’ stated intention that the statute be interpreted broadly so as protect against the “real danger” of confining the “scope of the author’s rights on the basis of the present technology” in the face of even “unforeseen technical advances.” When Congress’s development of the retransmission compulsory license is added to the mix, the case for liability becomes airtight. After 1966, the governing law affecting cable television evolved considerably. After the Supreme Court determined that cable television services do not implicate the copyright owner’s rights, Congress added Section 111 as part of its stated intention to legislatively reverse the Court’s Teleprompter and Fortnightly rulings. This provision establishes a detailed compensation regime whereby cable services are charged for sending over-the-air signals to their subscribers. Retransmission of those signals absent compliance with the provisions set forth in Section 111 or authorization from the copyright owner constitutes copyright infringement. Over the ensuing decades, Congress has cemented this proposition time and again.When taken together, the text, structure, and legislative history of the 1976 Act establish that Congress intended its public performance right to reach the Aereo service.

Fourth-generation Bidirectional Wireless Hybrid Transmission System Employing Power-Doubler-Amplifier and Data Comparator

Abstract An innovative cost-effective fourth-generation bidirectional wireless hybrid transport system, employing optical add-drop multiplexing technique, power doubler amplifier and data comparator, is proposed and experimentally demonstrated. The proposed system can transmits, downlink 80 community antenna television (CATV) channels, two different wireless-over-fiber (WoF) data signals (1.5-Gbps/2.4-GHz, 2.5-Gbps/3.5-GHz) at two different base stations over 40 km and 80 km single-mode fiber (SMF), respectively, and an uplink 5-Gbps baseband (BB) signal at central station over 40 km SMF, using a single optical carrier. The good carrier-to-noise ratio, composite-second order and composite-triple bit are achieved for CATV channels, and small BER and open eye-diagrams are achieved for WoF and BB signals.

Novel high gain and wide band hybrid amplifier designed with a combination of an EYDFA and a discrete Raman amplifier

In an optical communication network, over a broad range of spectrum, the gain of the amplifier must be flattened in order to increase the bandwidth utilization of the network. Here we analyze a novel approach of designing a hybrid amplifier with a combination of a single mode (SM) erbium ytterbium co-doped fiber amplifier (EYDFA) and a discrete Raman amplifier (RA) to flatten its gain over the optical spectrum of the C and L bands, which is about 90 nm of spectral width. This hybrid amplifier requires only 5 optimal pump signals in RA, and there is no need of any gain flattening filter in it. The performance of this simulated hybrid amplifier is analyzed with the help of 110*40 Gb/s non-return-to-zero dense wavelength division multiplexed (DWDM) signals as the input. They cover the entire C and L bands, and the presence of dense channels also ensures the accurate measurement of important parameters of the hybrid amplifier such as maximum gain, gain ripple, noise figure, and optical signal-to-noise ratio (OSNR). The five pump signals of RA are spaced equally, unequally, and semi-unequally in order to attain the objective. The least gain ripple is obtained for semi-unequal pump frequency spacing. The length of the SM EYDFA, the RA, the power of the pump signals, and the power of the DWDM input signals are optimized through the multi-parameter multi-target optimization tool of the Optisystem simulation software. The five pumping signals of RA are tested with forward, backward, and both forward and backward schemes in order to analyze the performance of the hybrid amplifier. Out of all the experiments, the SM EYDFA + RA forward pumping scheme offers superior performances such as maximum gain of 31.2 dB, very low gain ripple of 2.09 dB (6.7% of the maximum gain), maximum noise figure of 4.68 dB, and maximum OSNR of 34.23 dB. This new design of hybrid amplifier with superior gain flattening performance will be very much useful for cable television or community antenna television (CATV) and telecommunication networks.

光纤公共电视天线传输系统中短波通截止滤光片

光纤公共电视天线传输系统中短波通截止滤光片

An Integrated Long-Reach PON and GI-POF In-House Network Architecture for Hybrid CATV/OFDM Signals Transmission

We propose and demonstrate an integrated long- reach passive optical network (PON) and in-house graded-index plastic optical fiber (GI-POF) network architecture for hybrid community antenna television (CATV) and orthogonal frequency division multiplexing (OFDM) signals transmission. By reasonably multiplexing the OFDM and CATV signals into a CATV transmitter, both signals originated from a central office (CO) are successfully transmitted over a span of 60 km single mode fiber (SMF) and another span of 25 m GI-POF to consumers' devices. Although the SMF and GI-POF have different core sizes and attenuation features, no any bridge circuit or wavelength converter is utilized in the proposed architecture resulting in a transparent platform for the Internet service providers (ISPs) to directly manage their long-distance services toward suburban or rural areas. Since the optical signal generated at the CO can be transmitted straightforward to the consumers' devices, the average packet delay and packet overhead size can be greatly reduced and the quality of services (QoS) can be maintained easier. Good experimental performances of the CATV and OFDM signals transmission proof the practice and efficiency of this proposal to extend multimedia services from metro areas to suburban and rural areas.

IPTV가입자와 디지털 CATV가입자의 특성비교에 관한 연구

The object of study is to compare the characteristics of IPTV (Internet protocol television) subscribers and digital CATV (Community antenna television) subscribers. We used the adjusted residuals. We did gang survey for 100 subscribers in Seoul, Kyeonggi or Incheon regions. Compared to digital CATV, IPTV seems to have appropriate contents for interactive services and high satisfaction level for cost, but high dissatisfaction level for channels. Digital CATV subscribers would know and subscribe passively, compared to IPTV subscribers. IPTV subscribers are more satisfied than digital CATV subscribers even though IPTV is higher cost. Main content of digital CATV is sports, which is not interactive contents. People think IPTV is an innovative service which let subscribers see wanted contents always, but digital CATV is an extension of CATV. So digital CATV cannot use advantages of interactive services. Even though two services are almost same, they are very different in recognition.

Hybrid cable television and orthogonal-frequency-division-multiplexing transport system basing on single wavelength polarization and amplitude remodulation schemes

A hybrid community antenna television (CATV) and orthogonal-frequency-division-multiplexing (OFDM) transport system is proposed and experimentally demonstrated to transmit multiple CATV channels and bi-directional radio frequency signals on a single optical carrier. By polarization remodulating an optical CATV signal with downstream OFDM signals and then amplitude remodulating upstream OFDM signals with the hybrid CATV/OFDM signals, this architecture can efficiently utilize only one optical carrier to support optical analog/digital CATV transmission and bi-directional wireless broadband services for each client. Good experimental results prove that this architecture provides a proper wavelength utilization scheme for future multiwavelength optical transport systems.

Direct CATV modulation and phase remodulated radio-over-fiber transport system

A novel transport system, with directly modulating community antenna television (CATV) signal downstream and phase-remodulating radio-over-fiber (ROF) signal upstream, is proposed and experimentally demonstrated. By modulating multi-carriers CATV signal in amplitude domain and ROF signal in phase domain, a single optical wavelength is able to serve these two applications simultaneous. To be the first system of communicating CATV signal downstream and phase remodulating radio signal upstream, the performances of transmitting CATV and radio signals over 20 km single-mode fiber (SMF) were experimentally verified. Good performances of carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple beat (CTB) were obtained for CATV applications as well as high extinction ration (ER) and low bit error rate (BER) values were measured for ROF transmission.

Evaluation of the interference of pulsed UWB signals over current services in CATV installations

This paper presents an application of ultra- wide band (UWB) technology, consisting on the injection of pulsed UWB signals on community antenna television (CATV) installations. This approach offers the cable installers the possibility for a wide range of new data and multimedia channels on existing CATV installations, with a minimum cost and without altering the transmission of the traditional radio and television channels. The goal of this study has been to estimate the signal levels for which no harmful interference exists for the currently deployed services. Simulations and practical experiments were undertaken, and are presented and discussed in this paper.

A 60-GHz-Band Analog Optical System-on-Package Transmitter for Fiber-Radio Communications

We developed an analog optical system-on-package (SoP) transmitter for a 60-GHz-band radio-over-fiber (RoF) link. The SoP transmitter consisted of an electroabsorption modulator, radio frequency amplifiers, and a bandpass filter. The 60-GHz RoF wireless link was prepared to measure the performance of the SoP transmitter. The transmission characteristics of 64-quadrature amplitude modulation (64-QAM) data of the 60-GHz RoF wireless link, including the SoP transmitter, were investigated by measuring the error vector magnitude (EVM) and signal-to-noise ratio (SNR) with a baseband frequency. The EVM of the 60-GHz RoF wireless link was between 2.25% and 2.80%, and the SNR was between 27.36 and 29.31 dB from 140 and 770 MHz, at input baseband power of -9 dBm. The noise figure had the minimum of 8.44 dB at 500 MHz. We successfully transmitted digital community antenna television (CATV) system signals through the 60-GHz RoF wireless link, including the SoP transmitter. Digital CATV signals of 86 channels could be transmitted through the 60-GHz RoF wireless link, and the total throughput was found to be 2.61 Gb/s.

Full-Duplex DOCSIS/WirelessDOCSIS Fiber–Radio Network Employing Packaged AFPMs as Optical/Electrical Transducers

A hybrid fiber-radio access network architecture for simultaneous wireline and wireless transmissions of data-over-cable service interface specification (DOCSIS) signals is presented. An all-optical harmonic up-conversion technique using a dual-drive Mach-Zehnder modulator provides the downstream optical signal modulated not only at the intermediate frequency in the 600- to 900-MHz band for wireline transmission but also at the up-converted frequency in the 5.45- to 5.75-GHz band for wireless transmission. An InGaAsP/InGaAsP multiple-quantum-well asymmetric Fabry-Perot modulator/detector has been designed, fabricated, and packaged and has been employed in the base station (BS) as an optical/electrical transducer, simultaneously providing the functions of optical intensity modulation and photodetection. At the BS, the DOCSIS signals are recovered at the wireline and wireless frequencies for the respective feeding of a cable access network or a fixed wireless access network in a highly flexible approach. Full-duplex operation has been demonstrated for both access types in an indoor laboratory environment. In a subsequent small-scale field trial, real-life Internet traffic provided by a local community antenna television system operator has been transported over the present hybrid fiber-radio access network architecture, and simultaneous transmission of both DOCSIS and digital television signals has also been performed.

An adaptive fast expansion, loading statistics with dynamic swapping algorithm to support real time services over CATV networks

As the community antenna television (CATV) networks becomes ubiquitous, instead of constructing an entirely new broadband network infrastructure, it has emerged as one of the rapid and economic technologies to interconnecting heterogeneous network to provide broadband access to subscribers. How to support ubiquitous real-time multimedia applications, especially in a heavy traffic environment, becomes a critical issue in modern CATV networks. In this paper, we propose a time guaranteed and efficient upstream minislots allocation algorithm for supporting quality-of-service (QoS) traffic over data over cable service interface specification (DOCSIS) CATV networks to fulfill the needs of realtime interactive services, such as video telephony, video on demand (VOD), distance learning, and so on. The proposed adaptive fast expansion algorithm and the loading statistics with dynamic swapping algorithm have been shown to perform better than that of the multimedia cable network system (MCNS) DOCSIS.

Improvement of CSO/CTB Performances Employing Up-Converted and Polarization Modulation Techniques

A two-wavelength wavelength-division multiplexing (WDM) community antenna television (CATV) transport system that employed up-converted and polarization modulation techniques to reduce the composite second-order (CSO) distortion and optical nonlinearities is proposed and demonstrated. In contrast to a two-wavelength WDM CATV transport system using the intensity modulation technique, good performances of CSO and composite triple beat were obtained, accompanied by acceptable carrier-to-noise ratio value in our proposed system over a 100-km single-mode fiber transmission.

Measurement of gain tilt and its contribution to composite second-order distortion in the analog-digital transmission systems with Er/Yb fiber amplifiers.

Fiber-optic-based analog or digital community antenna television systems experience composite second-order (CSO) distortion caused by the interaction between the gain tilt of the doped fiber amplifier and the laser chirp due to modulation. The gain tilt for an analog-digital transmission system with a high-power erbium/ytterbium-codoped fiber amplifier has been experimentally measured and its contribution to the CSO distortion of the system is evaluated. The results are in good agreement when compared with the direct measurement of the CSO distortion of the transmission system with and without the amplifier. The dependence of the gain tilt on the modulation frequency and wavelength of the input light is also investigated.

Delivery of low rate isochronous streams over the digital video broadcasting/Digital Audio-Visual Council cable television protocol

This paper examines the capacity and performance characteristics of the digital video broadcasting (DVB)/Digital Audio-Visual Council (DAVIC) cable television protocol for the delivery of low rate isochronous streams for a cable population of up to 700 nodes. Streams (ranging from 8 to 128 kbps) suitable for timing critical services such as compressed/uncompressed voice (e.g., VoIP: G711 and G.7231), audio and low quality video, were considered in order to study the effects on channel capacity when using reservation and fixed access for the delivery of timing critical services. The analysis focuses on the,performance of the upstream channel, which is the limiting factor of community antenna television (CATV) networks and is critical in the delivery of services to individual subscribers on demand. Simulation results indicated that such streams, within the given protocol limitations, can be supported for a particular system population with trade-offs in terms of system throughput and channel utilization. Network capacity, in terms of the number of simultaneous streams supported and link utilization, is significantly affected by packet size. Analysis of the results indicated that for different streams, packet sizes and combined with header suppression, the benefits from the use of fixed access is essential for the support of timing critical services.

An Analytical Model for the Performance of the DOCSIS CATV Network

The Data Over Cable Service Interface Specification (DOCSIS) is established as the primary cable network data communication standard inNorth America and is the first specification having reached international standard level. It is therefore appropriate to determine its performance. Previous works on performance analysis of the DOCSIS Community Antenna Television network have been carried out using computer simulations. In this paper, we propose a model for mini-slot allocation with two priority classes of traffic which supports a real-time Constant Bit Rate (CBR) service and a non-real-time data service. Real-time CBR traffic has pre-emptive high-over-line priority over non-real-time data traffic. The service discipline is First Come First Served. Two critical characteristics, average delay and throughput, are analysed. Finally, numerical results are presented. The results demonstrate that the delay requirement of real-time CBR traffic can be easily met at the expense of the delay of non-real-time data traffic.

Recovery analysis of the DOCSIS protocol after service disruption

Wide scale power outages can cause serious disruptions to digital services over community antenna television (CATV) networks. This can result in long service recovery times for some or all of the cable modems (CMs). In this paper, the recovery mechanisms of the Data Over Cable Service Interface Specification (DOCSIS) protocol, due to service disruption, are studied. We propose a new scheme for the ranging of modems, namely persistent ranging algorithm (PRA) and two different simulation models have been developed for this purpose. The simulation results show that the static nature of the registration and initialization parameters can introduce an excessive delay in the recovery time of the system. Minimum recovery times of 820 s and 975 s (two ranging opportunities/second) for network architectures with 400 CMs and 500 CMs, respectively, on a single upstream channel were obtained. In order to validate the accuracy of the simulation models a set of experiments was performed on a CATV network testbed. The testbed results revealed that the simulation models produced are realistic and offer reliable estimates of large-scale network topologies. Extensions to the DOCSIS MAC protocol in which the status of the system prior to disruption is used have reported a decrease of up to 42% in the recovery time of the system.

Two tales of a city: John Walson, Sr., Mahanoy city, and the “founding”; of cable TV

For the last 20 years, scholarly and popular accounts of the development of cable television have recounted the story of John Walson, Sr., who claimed to have started the first CATV system in June of 1948 in Mahanoy City, Pennsylvania. When Walson died in March of 1993, newspapers around the country credited him with starting the nation's first cable system and even “founding”; the industry. The claim, however, has always been clouded by questions and a lack of documentation. This paper reports the results of an investigation of the Walson story. It concludes that, as bright and promising as the Walson tale may be, it probably is not true. At the very least, the preponderance of evidence suggests that Walson got his start in the community antenna television business in late 1950, about the same time as many others around the country and, importantly, probably after another group of businessmen already had begun a system in Mahanoy City itself.