Broadcasting | Audio/video headends Compact BTS gateway for
ISDB-TB networks
The R&S®AVG050 is a compact and versatile ISDB-T BTS gateway for ISDB-TB, a transmission standard mainly used in Latin America. The gateway is equipped with an integrated satellite receiver and remulti- plexer, making it ideal for use between the local encoding / multiplexing center and the transmitter.
Comprehensive functions The R&S®AVG050 ISDB-T BTS gateway (Fig. 1) has an inte- The R&S®AVG050 is also available as a grated satellite receiver and DVB-S / DVB-S2 demodulator for pure satellite receiver receiving and processing national programs. Local content is More and more infrastructures for transmit- usually fed in in standard-definition (SD) format. It is gener- ter networks and closed user groups such as ated in a local headend and can be fed to the R&S®AVG050 as business, hospital and hotel TV use IP-based a transport stream over IP or ASI (Fig. 2). The gateway multi- solutions. Since these applications often plexes the satellite-fed or locally fed content to a new trans- do not require any decoding in the receiver, port stream and generates a broadcast transport stream (BTS) the R&S®AVG050 is also available as a pure with the appropriate modulation parameters for the transmit- demodulator without remultiplexing func- ter and the corresponding signaling information (PSI/SI) for tion. The R&S®AVG050 DVB satellite receiver the receivers. model features two integrated DVB-S / DVB-S2 demodulators for receiving two The gateway has two common interface (CI) slots for condi- transponders. A built-in BISS descrambler tional access modules (CAM) used to decrypt the DVB-S / and two CI slots are provided for DVB-com- DVB-S2 signals and therefore supports two different encryp- patible decryption. After the incoming trans- tion methods at the same time. The R&S®AVG050 can also port streams are decrypted, the DVB satellite decrypt two signals scrambled according to the basic interop- receiver outputs them as IP or ASI signals. erable scrambling system (BISS) standard (BISS-1 and BISS-E). Key features of the R&S®AVG050 A clearly organized, intuitive user interface is provided for DVB satellite receiver: configuration and monitoring. All automatic monitoring com- ❙❙Two DVB-S / DVB-S2 receivers with mands and key device settings can also be remotely executed two CI slots via an SNMP interface. ❙❙Integrated BISS descrambling ❙❙ASI and IP outputs ❙❙Configuration and monitoring via SNMP ❙❙Compact: only one height unit and ½ rack width
Fig. 1: The R&S®AVG050 ISDB-T BTS gateway multiplexes satellite transport streams and locally fed components to a new BTS.
48 ISDB-TB transmission chain UHF
¸AVG050 ISDB-TB transmitter Fig. 2: The central encoding and (e.g. ¸SIx8000) TS over ASI or multiplexing center transmits the TS over IP transport streams via satellite to Studio Studio HD-SDI / SD-SDI the different transmitter sites. The DVB-S TS / DVB-S2 TS Central DVB-S / DVB-S2 Local encoding and TS or R&S®AVG050 uses the satellite-fed encoding and multiplexing multiplexing center compressed BTS and local programs to generate a center (e.g. R&S®AVHE100) (e.g. R&S®AVHE100) BTS RF new BTS for the transmitter.
Summary The R&S®AVG050 ISDB-T BTS gateway expands the prod- comprehensive functions. Since it is only half the width of a uct range for the Latin American market. In addition to trans- 19" rack, two gateways can be placed next to each other in mitters and T&M solutions for ISDB-TB , the portfolio now one height unit. In addition to space savings, it also offers the includes the appropriate BTS gateway with integrated sat- advantage of low power consumption. ellite receiver. The gateway is very compact, yet offers Claudia Görig; Denis Hagemeier
Typical topology of Since satellite-fed signals can be Unlike DVB-S / DVB-S2 transport
ISDB-TB transmitter networks received nationwide using common streams, the newly generated BTS
The ISDB-TB transmission standard set-top boxes, the programs are trans- has a fixed data rate of 32.508 Mbit/s for digital broadcasting is a modifi- mitted in encrypted form and only and a defined frame structure for cation of the Japanese ISDB-T stan- available to pay TV end users in the transmitting up to three layers (A, B, dard. It mainly differs from ISDB-T by respective transmitter region. These C) with different modulation and error using H.264/MPEG-4 AVC instead satellite streams have to be decrypted protection. Depending on the selected of MPEG-2 for video coding and at the transmitter site and subse- transmission parameters, the BTS MPEG-4 AAC instead of MPEG-2 AAC quently remultiplexed to a new BTS. It contains 30 % to 50 % null packets for audio coding. It is also used to is possible to add regional programs as placeholders. In addition to SD and transmit data services. during this process. CAMs inserted HD programs for stationary reception, in the satellite receiver’s CI slots are the BTS can contain 1seg programs
In ISDB-TB networks, national pro- usually used for the decryption. After for mobile reception at low data rates. grams are usually transmitted to the decryption, the newly generated BTS It is common practice in Latin Amer- transmitter site via satellite (DVB-S / is fed to the transmitter. ica to transmit three programs per
DVB-S2). The distances are often so ISDB-TB frequency: one HD program, large that the transmission of data 1seg program with the same content streams via optical fiber or micro- and an additional SD program. wave links is too costly, and some countries do not have the necessary infrastructure.
NEWS 209/13 49