BKtel equipment for Fiber Optic networks

By Andrey Pavlov

Review contents:

Fiber Optic technologies in broadcast sphere Profitt Company equipment for Fiber Optic links of video, audio and data transmission Axon equipment BKtel equipment for Fiber Optic networks Fiber Optics in TV and Radio broadcasting Kramer Electronics equipment for Fiber Optic lines of TV signal transmission Network Electronics equipment Snell & Wilcox Fiber Optic receivers and transmitters Equipment of Telecast Fiber Systems Company Optical node getting closer to the household Fiber Optic equipment from Vistek

German BKtel Systems Company initially existed as a structure division of Alcatel and had been specializing on end-to-end solutions in the field of building HFC and PON networks in developing of which the headquarter was as a system contractor. At present time BKtel is an independent company with Germany-based headquarter and production factory.

On a base of BKtel equipment tens of project (in Europe and worldwide) of modern television multiservise networks are realized using both classic HFC solution and xWDM technologies including PON networks,

BKtel equipment presents by four groups:

• 1570BB — optical modular headend. This is a power platform for solving tasks of any complexity connected with transmission/receiving optical signal in interactive television cable networks;
• BaalGiga — active optical equipment presented by separate 19" modules;
• BaalNano — passive optical components;
• BallFTTx — equipment for FTTx networks: compact optical receivers, Ethernet transceivers, media converters.

Geography of BKtel Company realized projects

Optical multifunctional 1570BB platform can be recommended for use as a transmitting/receiving headend for midsize and large CTV systems with return channel. Station’s configuration allows realizing redundancy according to 1+1 and N+1 for all its modules as well as do hot swapping of failed parts and perform remote control and monitoring. 1570BB platform contains:

External view of 1570BB platform — chassis for 10 modules

• 19" installation panels for 10 and 12 modules. Use of dockable 9S type connector allowed realizing a possibility of automated detection of number/numbers of slots and number of slots occupied by module;
• Power supplies/converters with a possibility of using both AC (220V, 50 Hz) and DC (48, 60 and 72V). For output voltage monitoring the front panel is equipped with test connector;
• Optical transmitters with direct modulation. Input RF signal range is 5…1000 MHz, non-linearity at output — ±0.5 dB. The transmitters range includes the following models: 1310 nm non-cooled with 3 and 6 dBm output power; 1310 nm cooled with 6, 8, 11 and 13 dBm output power; 1550 nm cooled with 6 dBm output power; 1550 nm CWDM and DWDM (according to ITU) with 6, 8 and 11 dBm output power;

Optical transmitter for 1310 and 1550 nm and its structure scheme

• Optical 1550 nm transmitters with external modulation. Output levels are 2×7 and 2×9 dBm. They have built-in input automated level control scheme;
• Family of optical EDFA amplifiers with the following characteristics: input level -4…+8 dBm; 1…8 outputs with 13 and/or 16 dBm output power depending on configuration; output non-linearity ±0.5 dB; automated output power switch off in a case of too low signal level on input; to monitor output power the testing optical output with 2 dBm signal level is provided;

Optical 1550 nm transmitter with external modulation

• Optical switchers with a possibility of automated and/or manual fiber commutation. Switching time is less than 50 ms; maximum optical power +24 dBm;
• Direct channel optical receiver: input — 1280…1580 nm with -7…+4 dBm level; output — 47…862 MHz with 1×98/2×94 dBµV;
• Optical transceiver — optical node for using within headend. It contains direct channel receiver (1280…1550 nm input with -4…+3 dBm level, 47(85)…870 MHz output with 92 dBµV level) and DFB transmitter of return channel (5…200 MHz input, 0 dBm output at 1310 and 1550 nm wavelengths including CWDM);
• Integrated active RF switcher of direct channel. It consists of signal router from two directions (switch time in automated mode less than 15 ms), amplifying cascade and divider to 4; it has test point on output;
• Return channel amplifier has smooth and step-by-step adjustments for equalizing return channel signals (5…70 MHz) from 4 directions as well as two-position output router;

Structure scheme of optical amplifier	Direct channel optical receiver

Optical tranceiver and its structure scheme

• Optical DWDM transmitter (according to ITU) of return channel: 5…300 MHz input with 77/87 dBµV level, output level +7 dBm;
• Quadruple optical return channel receiver. It has three RF outputs (5…200 MHz) for each receiver;
• 16-channel combiner-amplifier of return channel. It allows combining 5…200 MHz signals from 16 directions at any of following combinations: 1×16:1, 2×8:1, 4×4:1 with losses compensation;
• Remote monitoring and control modules (HMS protocol): RS-232, RS-485, Ethernet 10/100 — optical and RF inputs;

Structure scheme of return channel amplifier

Structure scheme of quadruple return channel optical receiver

• Optical nodes (2×99, 117 dBµV) with local/remote power feed and a possibility to install return channel transmitters including those based on WDWM technology. Protection class — IP65.
• Other RF and optical modules for configuring/amplifying of direct and return channels signals.

BaalGiga series modules are the devices built in 19" 1RU chassis. Control/monitoring buttons place on the front panel. There is a power supply (with a possibility of installing redundant power supply and the type of feeding voltage of this supply may differ from the main one). Such configuration allows avoiding extra expenses upon building cable TV networks with relatively small number of users or at solving narrow tasks, for instance, transmission the direct channel only using limited number of transmitters or at building the line with point-to-point topology. BaalGiga product range includes:

• 1550 nm optical transmitters with external modulation. Output power: 2×7, 2×8.5, 2×10 dBm. Power feed type 100…240V/50 Hz, 24, 36…72V DC or a combination. There is a possibility of remote monitoring/control and integrated module of automated level control on input. DWDM versions are available according to ITU;

1550 nm optical transmitter with external modulation

Optical switcher

• EDFA optical amplifiers family: -3…+6 dBm input level; 1…8 outputs with 13…23 dBm output power depending on configuration; output non-linearity ±0.5 dB; automated output power switch off in a case of too low input signal level; automated control of output power and amplification factor;
• Optical transmitters with direct modulation. Input RF signal range — 5…1000 MHz. The line consists of models: 1310 nm non-cooled with 3 and 6 dBm output power; 1310 nm cooled with 6, 8, 11 and 13 dBm output power; 1550 nm cooled with 6 dBm output power; 1550 nm CDWM, DWDM with 3, 8 and 11 dBm output power;
• Optical switcher with a possibility of automated and/or manual fibers commutation. 1540…1570 nm v\wavelength range; switch time less than 50 ms; nominal optical input power — -8…+15 dBm; maximum power — +17 dBm; number of commutation cycles — 107;
• Direct channel optical receiver: 1280…1580 nm input with -6…+2 dBm level; 5…1000 MHz output with 81 dBµV level; automated level control of output RF signal; low level of inter-modulation distortions;
• Double return channel optical receiver: 1280…1580 nm input with -11…+2 dBm level; 5…65 MHz output with 80 dBµV level;

Direct channel optical receiver

Remote monitoring and control module

• Remote monitoring and control module: RS-232, RS-485, Ethernet 10/100.

Passive optical equipment from BKtel shapes the BaalNano series which consists of optical xWDM multiplexers, splitters and dividers, filters, attenuators, dispersion compensators and commutation devices.

For realizing projects on delivery of wideband signal to end user or group of users involving FTTH and FTTB solution the company offers BallFTTx product line which has Ethernet transceivers and compact optical receivers in its range.

Compact optical receivers

Optical user’s FTTX modem

Compact optical receivers are considered as end user devices within realization of “Fiber to household/cottage/building” concept and in terms of price these devices are an alternative to coaxial solution when simplex signal transmission via separate optical core is used. For these devices an optical range of wavelengths is 1280…1580 nm; input level — -10…-2 dBm, output range — 47…862 MHz; output level — 77/88 dBµV; frequency response non-linearity — ±1dB, IM2/IM3 level — not less than 65 dBs.

Optical end nodes (Ethernet transceivers) allow besides cable TV providing Ethernet and VoIP services. In a case of single fiber connection to the node the Ethernet receiving/transmitting is being performed on 1310 wavelength and TV reception — on 1550 nm wavelength. When using two-fiber version of transceiver the first one is used for cable TV (1280…1580 nm) while second one is used for data transfer in duplex mode (1550 nm band serves for ingoing services and 1310 nm band serves for outgoing traffic).

The nodes have LAN interface 4xRJ45 (IEEE802.3 10Base-T, IEEE802.3u 100Base-TX), voice interface 2xRJ11 (VoIP FXS), USB2.0 interface. Ipv4, TCP, UDP, DHCP, NAT, IGMPv2, PPPoE, PAP, CHAP, SIP 2.0, G.711, G.723.1, G.729a/b, RTP/RTCP, TFTP, HTTP, SNMP v1, Telnet, ARP, DTMF, IEEE802.3, IEEE802.3u, IEEE802.3x, IEE802.1p/Q, IEE802.1d and IEE802.11b/g protocols are supported.

In the present time BKtel equipment goes through the certification procedure.

Material provided by LANS Corporation