Outline of EWBS Module
Chapter 1 Introduction of EWBS 1
Configuration of EWBS Signal Emergency information is telecast in combination of TMCC signal and TS (Transport Stream). Information Source Encoding Part Transmission Route Encoding Part Video Encoding Video Layer Processing Audio Encoding Audio Error Correction Multiplexing Part TS Modulation Data Encoding Data Remulti Interleave OFDM plexing Transmission TMCC signal ・ ・ wave generating ・ Frame EWBS Configuration Data Encoding Character Information Formation Information EWBS Activation Flag EWBS Area (TMCC_B26) Information （ PMT) 2
What is TMCC Signal? Transmission and Multiplexing Configuration Control Parameters such as “in which mode should the signal be demodulated?” are described. EWBS Activation Flag is included for the purpose of power control. Carrier Number 0 1 2 3 4 5 6 7 8 9 10 11 12 0 SP S S S S S S S S S S S SP ・・・ ・・・ S 0,0 1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0 9,0 10,0 95,0 1 S S S SP S S S S S S S S S ・・・ ・・・ S 0,1 1,1 2,1 3,1 4,1 5,1 6,1 7,1 8,1 9,1 10,1 11,1 95,1 2 S S S S S S SP S S S S S S ・・・ ・・・ S 0,2 1,2 2,2 3,2 4,2 5,2 6,2 7,2 8,2 9,2 10,2 11,2 95,2 3 S S S S S S S S S SP S S S ・・・ ・・・ S 0,3 1,3 2,3 3,3 4,3 5,3 6,3 7,3 8,3 9,3 10,3 11,3 95,3 4 SP S S S S S S S S S S S SP ・・・ ・・・ S OFDM Symbol Number 0,4 1,4 2,4 3,4 4,4 5,4 6,4 7,4 8,4 9,4 10,4 95,4 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ TMCC ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Frequency ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 199 SP S S S S S S S S S S S SP ・・・ ・・・ S 0,199 1,199 2,199 3,199 4,199 5,199 6,199 7,199 8,199 9,199 10,199 95,199 200 S S S SP S S S S S S S S S ・・・ ・・・ S 0,200 1,200 2,200 3,200 4,200 5,200 6,200 7,200 8,200 9,200 10,200 11,200 95,200 201 S S S S S S SP S S S S S S ・・・ ・・・ S 0,201 1,201 2,201 3,201 4,201 5,201 6,201 7,201 8,201 9,201 10,201 11,201 95,201 202 S S S S S S S S S SP S S S ・・・ ・・・ S TMCC 0,202 1,202 2,202 3,202 4,202 5,202 6,202 7,202 8,202 9,202 10,202 11,202 95,202 203 SP S S S S S S S S S S S SP ・・・ ・・・ S 0,203 1,203 2,203 3,203 4,203 5,203 6,203 7,203 8,203 9,203 10,203 95,203 OFDM Segment Configuration 3
What is TS Signal? Transport Stream Broadcasting contents such as video, audio, etc., as well as broadcasting information such as datacasting, emergency warning, etc. are multiplexed into the TS signal. In EWBS, emergency warning information is distributed by using PMT and character superimpose packets. Video Video PAT Audio Video PMT DATA Video EIT Audio Video Video DATA TOT Video 188Byte TS is something like a ship container, carrying video, audio, program distribution information, etc. Compressed video, audio, contents for datacasting, etc. are divided into pieces; and they are transmitted serially in the TS packets of 188 byte each. An ID number, called PID, is allocated to each of the packets; in a way that what sort of information is included in each of the containers can be identified. 4
PAT … Program Association Table (PID = 0 x 0000) PID of PMT is written in. The number of PMT is the same as that of services provided. PMT … Program Map Table (PID = Described in PAT.) PID of the name of program, video, audio, etc. as well as the format of video, audio, etc. are written in . Area code for EWBS and PID of character superimpose packets are also written into the PMT. PAT PMT (1) Program name PMT(1) PID VIDEO stream Video Video PID Video format Audio PID Audio AUDIO stream Audio format Data PID DATA stream Data EWBS Area EWBS Text PID EWBS Text stream EWBS Text … EWBS Area PMT (2) PMT(2) PID PMT(3) PID 5
Composition of EWBS Receivers Antenna TS TS Emergency Carrier RF -> IF FFT Analyzing Demodulation Information Part TMCC TMCC TMCC signal is extracted from the Tuner. Once TMCC_B26 is changed to "1", TS Analyzing Part should be activated for TS analysis. Targeted area of emergency warning is detected from PMT in the TS packet. Contents of warning are extracted from the character superimpose packet of TSP. 6
Chapter 2 Hardware of EWBS module 7
EWBS Module Newly developed module for EWBS reception, to be incorporated into simplified EWBS receiver or TV receivers. 40mm 25mm 8
Features of EWBS Module Size: 40mm X 25mm SMD/DIP(2mm pitch) Power 3.3V Single power supply Power consumption: 190mW in standby, 248mW when receiving EWBS Applicable frequency: UHF 470MHz ～ 806MHz Bandwidth: 6MHz/8MHz 1-seg Reception: Approx. 13dB higher than Full-seg reception When area code is set, emergency warning is received only in the pre-set areas. When area code is not set, emergency warning is emitted unconditionally. Output of EWBS reception flag Emergency information is emitted from serial port. Standard specification: UART I2C, SPI specifications also available. 9
Functional Flow of EWBS Module Receiving program of preset channel No TMCC(B26) = 1 Yes Activate Searching TS Analyzing Part character packets Check area code Decoding character data Make output of Make output of EWBS receiving flag character information 10
Wide Applications of EWBS Module Public Electronic Signage Small Display for home use Incorporation into wrist watches TV Receivers, Set-top Boxes Accessories measuring instrument of reception sensitivity 11
Chapter 3 Software of EWBS module 12
Commands of EWBS Module Setting UART 115,200bps, 8bit, 1 stop bit, no parity, no flow control Command Format Command packet format (Host → Module) Header Body Trailer STX TYPE Cmd Chk Data Data EXT 0x02 0x1D code SUM Size 0x03 Response packet format (module -> host) Header Body Trailer STX ACK Cmd Chk Data Data EXT 0x02 NAK code SUM Size 0x03 ChkSUM : (STX) + (TYPE) + (CMD) + (ChkSUM) + (DataSize) + (DATA1) + (DATA2) + ... + (EXT) = 0x****00 13
List of Commands CMD_GET_EWBS_INFO (0x11) Confirm the version of EWBS module CMD_GET_EWBS_STATUS (0x26) Obtain broadcasting conditions of EWBS signal CMD_GET_EWBS_RSSI (0x27) Obtain receiving conditions of EWBS signal CMD_GET_EWBS_TXT (0x28) Obtain character data of EWBS CMD_GET_AREA_CODE (0x24) obtain channel and area code information being monitored CMD_SET_AREA_CODE (0x25) Set channel and area code of the channel to be monitored 14
CMD_GET_EWBS_INFO Confirm the version of Module Command packet format (Host → Module) Header Body Trailer STX TYPE Cmd SUM Size Data EXT 0x02 0x1D 0x11 0xCD 0x00 None 0x03 Response packet format (Module -> host) Header Body Trailer STX ACK Cmd SUM Size Data EXT 0x02 0x06 0x11 0xF5 0x0B 0x45 0x57 0x42 0x53 0x03 0x5F 0x6D 0x6F 0x64 0x01 0x03 0x10 Data : EWBS_mod ver.1.3.16 15
CMD_GET_EWBS_STATUS Obtain receiving conditions of EWBS signal Command packet format (Host → Module) Header Body Trailer STX TYPE Cmd SUM Size Data EXT 0x02 0x1D 0x26 0xB8 0x00 None 0x03 Response packet format (Module -> host) Header Body Trailer STX ACK Cmd SUM Size Data EXT 0x02 0x06 0x26 0xB4 0x01 0x03 0x03 Receiving “Data = 0x03 EWBS Signal”, and play out alert sound. 16
Flow of Emergency Signal Reception EWBS Module Host CPU [EWBS_out] → H EWBS Reception EWBS Status Inquiry CMD_GET_EWBS_STATUS Command Response (status) No status_bit0 == 1 Yes CMD_GET_EWBS_TEXT Obtain character information (text_data_size=0) Completion of No text reception (text_data_size + Character_code) Yes Yes text_data_size=0 No Display of character data [EWBS_out] → L End of EWBS End of Alarm Sound Switching off of character data indication 17
Chapter 3 Applied example of EWBS module 18
Public Electronic Signage ● Normally displaying information, ads, time, etc. ● Upon receiving EWBS, the display is switched to warning information. LED display UART Control Unit USB LAN PC LAN Speaker ＋ Memory card LCD Panel insert HDMI Media for information, ads, etc. 19
Example of Control Circuit of Public Electronic Signage PC LED Display LAN uSD POWER (3.3V) GPIO EWBS Beagle Bone Black EWBS_DET Antenna GPIO module CPU Board SIREN UART UART RS-232C LED Display command HDMI USB LED Display USB Speaker LCD Panel 20
21
Recommend
More recommend
