Spd-t1/802

Transcript

SPD-T1/802 T1/E1 Rate and Interface Converter • FEATURES • Enables T1 (1.544 Mbps) equipment to operate over E1 (2.048 Mbps) facilities DESCRIPTION • • Complies with ITU G.802 standard (Annex B) • Controlled slip for buffer overflow/underflow • Loopback capabilities on • both T1 and E1 interfaces • T1 interface compatible with AT&T TR-62411 • E1 interface complies with ITU G.703, G.704 and G.823 standards • Transparent to T1 framing • SPD-T1/802 is a T1 to E1 (CEPT) rate and interface converter, enabling T1 equipment operating in pairs to utilize E1 (2.048 Mbps) transmission media. SPDT1/802 is transparent to the T1 framing pattern, allowing D4 or ESF to be accepted. Only the line code needs to be selected. • Jitter attenuation on both the T1 and E1 side guarantees smooth operation without timing or jitter-related errors. SPD-T1/802 supports all timing situations using the following strap-selectable timing options: - Transparent: E1 transmit clock is locked to T1 receive clock, and T1 transmit clock is locked to E1 receive clock. - Loopback: E1 transmit timing is derived from E1 receive clock, and T1 transmit timing from T1 receive clock. - Internal: An internal oscillator acts as a timing generator for both transmit signals. • • For applications where both sides cannot be synchronized to a single network clock, an independent elastic buffer for each transmission direction compensates for short-term deviations in the timing sources. Each buffer size is four frames (772 bits). For overflow or underflow conditions, the buffer is positioned at the center (skipping or repeating four frames), to prevent violation of the T1 frame synchronization pattern. SPD-T1/802 supports two mapping schemes in which timeslot zero is used for framing the alignment signal according to the ITU G.704 standard. According to the strict G.802 mapping scheme, timeslots 1 to 15 and 17 to 25, plus bit 1 of timeslot 26, are loaded with 193 T1 bits. According to the modified G.802 mapping scheme, timeslots 1 to 24, plus bit 1 of timeslot 25, are loaded with 193 T1 bits. SPD-T1/802 transmits an unused code on unused timeslots. Diagnostic tests are supported by activating the T1 loopback towards the local DTE or the E1 loopback towards the remote DTE. Additional diagnostic features are provided via the front panel LED indicators showing loss of signal condition, excessive bipolar violations, and AIS for the T1 and E1 link. SPD-T1/802 is available as a desktop unit. A rack-mount adaptor kit enables installation of one or two units into a 19” rack. SPD-T1/802 T1/E1 Rate and Interface Converter • SPECIFICATIONS • E1 Interface Complies with: ITU G.703 Bit rate: 2.048 Mbps Line code: HDB3 Jitter performance: As per ITU G.823 Receive signal level: 0 to –10 dB • Unbalanced Interface: Pulse transmit level:±2.37(±10%) Impedance: 75Ω Connector: 2 BNC coaxial • • • Balanced Interface: Pulse transmit level:±3.0V (±10%) Impedance: 120Ω Connectors: 15 pin D-type, female T1 Interface Complies with: AT&T TR-62411, ITU G.703 Bit rate: 1.544 Mbps Line code: AMI or B8ZS, strap-selectable Jitter performance: As per AT&T TR-62411 Pulse transmit level:±3.0V (±10%) Receive Signal level:0 to –10dB Impedance: 100Ω, balanced Connector: 15 pin D-type Framing E1 link: G.704 T1 link: As per ITU No framing required • • • Timeslot Mapping Scheme Strap-selectable: Strict G.802 mapping: TS 1-15, TS 17-25, bit 1 in TS 26 Modified G.802 mapping: TS 1-24, bit 1 in TS 25 • Timing Strap-selectable: Transparent Loopback Timing Internal Timing (±32 ppm) • Elastic Buffer Buffer length: ±4 T1 frames Underflow: 4 buffer frames repeated while new data is enabled Overflow: 4 buffer frames skipped/lost (No T1 frame sync loss for buffer overflow/underflow) Data delay: Up to 1 ms Unused Code 54 hex on unused timeslots Diagnostics Local T1 loopback Local E1 loopback Alarm Responses Received Impairment on E1: Loss of signal/frame, AIS Transmitted response on E1: Yellow alarm Transmitted response on T1: AIS Receive Impairment on T1: Loss of signal, AIS Transmit response on T1: None Transmit response on E1: AIS • • • Indicators Power, Test, Loss of signal (T1 or E1) BPV (T1 or E1), AIS (T1 or E1), E1 loss of frame (Local and Remote) Controls Two switches for loopback tests Power Supply 115/230 VAC (±10%) 47 to 63 Hz; 15W –48 VDC (±10%) –24 VDC (±10%) Physical Height: 44 mm / 1.8 in Width: 216 mm / 8.5 in Depth: 242 mm / 9.5 in Weight: 1.75 kg / 3.74 lb Environment Temperature: 0 to 50°C / 32-122°F Humidity: Up to 90%, non-condensing ORDERING SPD-T1/802/* T1/E1 Rate and Interface Converter * Specify: 115 for 115V power supply 230 for 230V power supply -48 for -48V power supply -24 for -24V power supply RM-1 Hardware for mounting one or two units into a 19" rack APPLICATION 263-100-03/98  1998 RAD Data Communications Ltd. Specifications are subject to change without prior notice.