1. Enhanced Television Program Quality
With digital signal transmission, noise does not accumulate, ensuring uniform signal quality across all users and significantly improving broadcast reliability. Currently, 16 provinces and municipalities in China, along with CCTV, utilize digital satellite television programs. DVDs (Digital Versatile Discs) have also entered the market. By adopting the MPEG-2 video coding standard (video bitrate: 4–5 Mb/s), digital CATV systems can deliver signals with a resolution of 704×576 (480-line display), achieving a subjective visual quality rating of approximately 4.3 points compared to the 3-point rating of analog systems. This represents a one-tier improvement in image clarity. Furthermore, digital systems enable the transmission of High-Definition Television (HDTV) programs.
2. Increased Program Capacity
China’s analog TV standard (PAL D/K) uses an 8 MHz channel bandwidth. With digital modulation (64QAM), a single 8 MHz analog channel can transmit 8–10 digital TV programs. Within a 200 MHz bandwidth, 200–250 programs can be delivered. While international standards often recommend the 550–750 MHz band, domestic cable operators in China have repurposed analog channels, enabling the use of supplementary frequency bands (250–450 MHz). This expanded capacity supports advanced services such as Video on Demand (VOD), HDTV, and multimedia information delivery within CATV systems.
3. Diverse Service Offerings
Digitization unlocks new possibilities for CATV, enabling interactive services previously impossible with analog technology. These include telephone services, internet browsing, TV shopping, e-banking, distance education, and conditional access services like VOD. Users transition from passive viewers to active participants.
PBI Digital CATV Headend Solution
PBI provides cable operators with a comprehensive, end-to-end solution and suite of front-end products:
Signal Processing & Multiplexing
Source Handling: Decoders and encoders process satellite, in-house, and SDH-transmitted programs.
Remultiplexer: Aggregates multiple program streams into a single transport stream, supporting 8 independent inputs and 2 outputs.
Scrambler: Integrates with a Conditional Access System (CAS) for tiered content authorization and management.
QAM Modulator: Converts streams into digital RF signals for network distribution, supporting 16–256 QAM modulation schemes. An optional DS3 interface enables direct SDH network integration.
Network Management & Value-Added Services
Centralized Control: Web-based software enables unified device management and monitoring.
Enhanced Features: Supports Electronic Program Guides (EPG), data broadcasting, and closed captioning for advertising.
Style Adjustments:
Simplified technical jargon for clarity while retaining precision.
Structured content with concise headings and bullet points for readability.
Emphasized key advancements (e.g., "enhanced," "increased," "diverse") to highlight benefits.
Standardized terminology (e.g., "QAM," "CATV") for consistency.
1.PACIFIC 提高了电视节目的质量
数字化以后的电视信号传输，噪声没有积累，各用户的信号质量一样， 提高了传输质量。我国目前有16省市和中央电视台都用了数字卫星电视节目，DVD（数字视盘）也已经上市。采用MPEG－2视频编码标准，视频比特率为4~5Mb/s，利用这些数字信号源，使用数字CATV（有线电视）传输到用户，图像尺寸（取样数×扫描行）704（720）×576（480），可将显示清晰度提到480线，主观评价约4.3分。与模拟的3分左右相比，图像等级提高1级。还可以传送高清晰度电视节目。
2. 增加了电视节目的数量
我国电视的模拟制式为PAL D/K，频道带宽是8MHz。CATV采用数字调制方式为64QAM，1个8MHz模拟频道可以传8～10套数字电视节目。 200 MHz带宽内可以传200～250套节目。国外有的推荐用550~750MHz频段，国内某些有线电视台已由模拟频道占用，也可使用250～450 MHz的增补频段。这样在CATV系统中就可以开展VOD（视频点播）、HDTV（高清晰度电视）及其它多媒体信息业务。
3. 能提供多功能业务
随着CATV的数字化，以往用模拟方式无法提供的电视业务都将成为可能，可以实现数字业务、交互式电视业务等新型服务方式，如提供电话、计算机浏览等业务，也可提供电视购物、电子银行、远程教育、VOD等新式有条件接收的交互式业务。用户从单纯的收视者变为积极的参与者。
PBI数字有线电视前端解决方案为有线网络运营商提供了一套完整解决方案及一系列前端产品。
节目源部分，解码器、编码器分别完成从卫星、自办节目、SDH传输节目的接收处理。处理后的码流进入再复用部分，将多个单节目码流再复用生成一个多节目码流，支持8路独立输入和2路独立输出。再复用后的码流进入加扰器，配合CAS可对码流中的节目进行分类、分级授权管理。通过QAM调制器的调制成数字射频信号送入网络。可满足16~256QAM间的各类调制方式。选配DS3输出接口便可调制后直接送入SDH网络。
客户可通过网络软件对系统中的设备进行统一管理和监控。可在系统加入EPG、数据广播、广告字幕等增值服务。
