2 Way MMDS
home:TELECAST TECHNOLOGY >> Solution >>2way MMDS (WIRELESS " TRIPLE PLAY " SYSTEM)
System description;
1. System bandwidth: 200M (2500-2700M,or 2100
2. There are three frequency plans:
1. DTV and data are working in different frequency bands. All TV programs and DATA are compressed and packaged by the Head-end, then are sent out as downstream signal. At the subscriber’s side, transceiver will receive the down-stream signal and send upstream request.
The system is a true multi-service platform that can transmit multiple carriers and multiple access systems, including shared bandwidth access systems as well as MPEG2 digital video, VOD (Video-on-Demand), wireless IP data, video conference and high-speed private networks.
The system can accommodate MULTIPLE carriers, each only 6 MHz wide, EACH with a data transmission rate of 45 Mbps downstream and 15.6 Mbps upstream.
•Downstream:
– Usually use 16 or 64 QAM or QPSK modulation
– Channel Bandwidth Options : 6 MHz ( DOCSIS )
8 MHz ( Euro DOCSIS )
– Data Rate per Channel : 30 Mbps per 6 MHz Channel
40 Mbps per 8 MHz Channel
– Each 6 MHz channel may serve 5000~10000 subscribers, and 100~500 simultaneously active
• Upstream:
– Usually use QPSK.
– Channel Bandwidth ( Data Rate ) Options : 400kHz ( 640kbps )
800kHz (1.28Mbps )
1600kHz (2.56Mbps )
If the head-end transmits more downstream data channels, the subscriber will get faster internet.
2. If the transmitting point is high enough, it can cover omni directional 50-100Km directly.
3. After being multiple relayed, the signal can be transmitted to more than 400Km.
4. The system can be conveniently upgraded to 2WAY MMDS (TRIPLAY PLAY SYSTEM), so as to conduct more business to increase the revenue.
5. The transmission can be point to point, point to multipoint or point to face.
6. The system can transmit SD and HD digital TV programs simultaneously, and the image is much clearer.
7. The subscriber must use STB and SMART CARD to receive the signal, so it is very convenient for operator to manage the charges.
8. All Head-end equipment can be accessed into NMS for software management, and the whole system is controlled and managed by CAS and SMS.
9. The system has the function of PPV (PAY- PER –VIEW), PPT (PAY- PER –TIME), EMAIL, OSD and EPG.
10. If choose QPSK modulation mode, the STB not only can receive MMDS signal, but also can receive free satellite TV programs when adding a satellite LNB.
11. The transmitter and CAS&SMS support remote monitor and control.
12. STB supports online upgrading
13. The subscriber can use scratch card (telephone voice recharge system and short message recharge system) to recharge.
How to require design and quotation
Telecast will be happy to help you define an MMDS system to fit your special requirements.
1. How many TV programs would you like to broadcast? Note: 24 PAL or 30 NTSC at most.
2. How high is the transmitting point? That is, the altitude of the transmitting point plus the height of the building plus the height of the tower. The higher transmitting tower, the more signal coverage.
You had better to send us a picture of the tower, especially the picture of the position where the antenna may be installed, as well as the dimension of the supports, so that we can design the accessories of the antenna.
3. What is the distance from the studio to the top of tower?
Because we want to know how long the cable will be used from the studio to the transmitting antenna.
If the distance is over 150m, you should use optical fiber or a wireless point to point link system (STL).
4. What is the available frequency band? Is it 2500-2700MHz or other special?
2500-2686MHz is the standard frequency band that international organization ITU has assigned to radio and TV transmission. Generally, we use this frequency band. But if this frequency band has been occupied, you can choose 2100-2300MHz or 2300-2500MHz.
No matter what frequency to use, you must ensure that no one use the same frequency in the same area. In other words, you should get frequency license from your government.
5. What is the radius of the coverage? For example: 30KM or
6. What is the angle（width）of the coverage area? 90 or 180 or 360 degree omni-directional?
This will determine the choice of antenna. The narrower transmitting angle, the higher gain antenna can be used. Thus, you also can use a lower power transmitter to reduce the system cost.
Therefore, you’d better provide the map of the coverage area or the name of the city.
7. Please try your best to offer us the parameter of the programs which are received from the satellite, just like the DOWN FEQUENCY, SYMBOL RATE, FEC and WHICH CAS. You can get these parameters from the website: www.lyngsat.com.
If not all programs are from satellite, please tell us the numbers of satellite programs and local analogue programs (require MPEG encoding)
8. Can you apply for faster speed and more bandwidth ISP access from your local INTERNET service provider?
After getting the exact answers for these questions, we will provide you with a suitable solution and pricelist.