Digital Video Processing - Video Services in Hong Kong
Video Services in Hong Kong
Types of video services available in HK (Broadcasting Landscape) :
- Terrestrial TV services (Free-to-air TV)
- Through the transmitter on the top of the mountain
- Satellite TV services
- Through the Satellite
- Cable TV services
- Through the Cable
- Over-the-Top(OTT) (TV/Video services through Broadband Network)
- Through the Internet
Terrestrial TV services
The Terrestrial TV services in HK:
- Television Broadcasts Limited (TVB; 無綫電視)
- Radio Television Hong Kong (RTHK; 港台電視)
- Owned by Hong Kong government
- HK Television Entertainment (HKTVE; 香港電視娛樂)
- Owned by PCCW
- Offer ViuTV
- Fantastic Television Limited (FTV; 奇妙電視)
- Offer OpenTV
Terrestrial TV services in HK:
- have almost 100% local household penetration (Cover all HK)
- using analogue/digital technology (analog phased out in Nov. 2020)
- analogue technology: susceptible to noise and interference (more sensitive)
TV signals are:
- sent from transmitting antenna through local radio airwave
- captured by an antenna at top of roof to display on a TV.
Terrestrial transmission:
- standard analog UHF (Ultra High Frequency) of 8MHz.
- Each TV program occupie 8MHz
Terrestrial TV services are the least expensive method of broadcast.
- Airspace is highly regulated (governed by Office of the Communications Authority (OFCA))
- Allowing a fixed number of available channels in any given location.
Frequency Division Multiplexing
- Different TV channels occupy different frequency bands
To switch the watching channel, just need to change the frequency.
SFN V.S. MFN
Disadvantage of Terrestrial TV service
- Since both the transmitter and receiver are at ground level (comparing to satallite)
- transmitter antanna on the top of the mountain
- large building, hills, mountains, etc, between the transmitter and receiver all impair the transmitted signal
- give rise to poor reception.
- To cover a wide geographical area, it requires a significant number of transmitters distributed around the total reception area.
- need to build a number of tranmitters
For Digital TV, they use both SFN and MFN.
For Analog TV, they all use MFN.
SFN (Single-frequency Network)
A single-frequency network or SFN is a broadcast network where several transmitters simultaneously send the same signal over the same frequency channel.
Advantage:
- Only one frequency channel is required to cover the service area
Disadvantage:
- If tranmitters’ covering area overlapped, ghosting (shadow of video frames) will happen due to echoes of the same signal (multi-path)
MFN (Multiple-frequency Network)
The signal from the program source to the distributed set of transmitters can be sent by microwave links or land lines, typically optical filter
Advantage: Each transmitter operates in a different frequency band to avoid ghosting
Disadvantage: Need to allocate more frequency bands than SFN (Single-frequency Network)
Digital Terrestrial TV
- In Digital TV, modulation will solve the ghosting problem in SFN.
Benefits of Digital Terrestrial TV
- Improved reception and picture quality
- Support new services like high definition television (HDTV) and multimedia / interactive services
- Carry more contents in one channel
- Support mobile / portable reception (Not only stationary TV, but also mobile devices)
- Better use of frequency spectrum
- Release valuable frequency spectrum for other uses after full migration from analogue to digital broadcasting
How to receive Digital Terrestrial TV
The Government announced on February 11, 2019 that the Chief Executive in Council has approved to proceed with switching off analogue television services (ASO) on November 30, 2020 (11.59pm). Hong Kong will enter an era of full digital TV broadcasting on December 1, 2020 (00.00 hours).
J2 Channel, I News, Pearl, J5 Channel (All owned by TVB)
RTHK TV 31, RTHK TV 32, RTHK TV 33 (owned by RTHK)
they are using single frequency network (Digital TV).
Satellite TV services
The Satellite TV services available in HK:
- Star TV (Satellite Television Asian Region, an Asian TV service owned by 21st Century Fox): access to satellite program through Satellite Master Antenna Television (SMATV) systems.
- TVB Pay Vision Limited: has launched its service in August 1998. (Shut Down on 1/6/2017)
- Through satellite transmission, TV signals can be amplified, and carried long distance by an orbiting satellite.
- (located some 20,000 miles from the Earth’s surface)
- Households equipped with a satellite receiver dish and decoder to unscramble the satellite’s signal such that TV sets can obtain this wider coverage and channel selection.
-
Digital satellite transmission
- Available thro’ direct broadcast satellite (DBS) is now commonly available.
-
For consumer, it requires the installation of
- digital satellite dish
- digital decoder
- monthly subscription to services
Cable TV services
The Cable TV services available in HK:
Hong Kong Cable TV Limited (Wharf Cable): 1993
- About one-third of its subscribers receive their signals through Hybrid-Fibre-Coaxial (HFC) cable delivery, and the remainder through Microwave Multipoint Distribution System (MMDS).
- Standard cable sends programming thro’ Hybrid Fiber Coaxial (HFC).
- uses fiber links from the central site to a fiber node, and coaxial cable from there to a home
- Cable is available through subscription services (Monthly fee) from a local cable operator, and requires the hook-up of a cable box.
TV services through Broadband Network
TV services through Broadband Network available in HK:
- Now TV (operated by PCCW media limited)
- provides interactive multimedia services
- Pay TV service provider in HK (197 channels)
- Internet Protocol TV (IP TV) /Internet TV or Over-the-Top (OTT)
- myTV Super
- Netflix
- YouTube
- …
- Keypoint: Use the Internet to transmit to user-end
Possible Home Access in HK
The full landscape:
How to coordinate them?
- Wireless via In-building Coaxial Cable Distribution System (IBCCDS)
- Hybrid Fiber Coaxial (HFC) via IBCCDS
- Internet
To use only 1 Socket to recieve all 3 signals:
Industry Convergence
產業融合(Industry Convergence)產業融合是指不同產業或同一產業不同行業相互滲透、相互交叉,最終融合為一體,逐步形成新產業的動態發展過程。
The telephone (telecommunication) industry, the television (broadcast) industry and the Internet industry once existed separately with specialized infrastructure to deliver their respective services.
- Telecom industry: built on specialized circuit switched network technology, a multibillion dollar telecom switch and equipment industry, to deliver “telephony” or “voice” services to consumers.
- Television (broadcast) industry: used specialized broadcast network technology to deliver television (video broadcast) services to consumers.
- Internet industry: Broadband access to the Internet was also offered as an independent service by broadband service providers, such as PCCW, HKBN for Internet (data) services.
With technological advances, these apparently independent industries are converging and are contending in the same digital content distribution space
Before | After | |
---|---|---|
Telecom (Voice) | Specialized Circuit-switched Network for Voice | Voice is an Application on the Internet |
Broadcast (TV) | Specialized Broadcast Network for Television | Television is an Application on the Internet |
Internet (data) | Packet-switched Network designed for non-real-time Applications: Email & Web | Network enhanced to support Real-time Applications: Voice & Video |
Reasons for Industry convergence
- Analog content is being replaced with digital content.
- content, no matter what industry it belongs to, is converted from analog to digital and then packaged into small units called packets.
- Network infrastructure is converging into a common packet-switched Internet protocol (IP)-based network technology, which is capable of carrying packets in an efficient manner. Naturally, all content, voice, video and data, are being transported over the common network.
Device Convergence
Consumer electronics and communications functionality are converging onto consumer devices.
Before | After | |
---|---|---|
Laptop/PC | Used for Web and Email | Used for Web and Email + voice, video |
Mobile phone | Used for making phone calls | Used for phone + Web, Email, IM, camera, video, MP3 player, AM/FM radio, PDA etc. |