Valiant Communications Limited Slide 1 E1 Automatic Protection Switching Solution (1+1 E1 Redundancy Switch) Updated : January, 2006 V aliant C ommunications L imited Telecom Transmission Solutions U.K. Valiant Communications (UK) Ltd 1, Acton Hill Mews, Uxbridge Road, London W3 9QN, United Kingdom Website: U.S.A. Valcomm Technologies Inc Ponce de Leon, Suite 470 Coral Gables, FL United States of America Website: INDIA Valiant Communications Limited 71/1, Shivaji Marg, New Delhi , India Website:

Valiant Communications Limited Slide 2 E1 Automatic Protection Switching Solution Basic Theory of Operation E1 Redundancy Switch is designed to provide 1+1 redundancy support for two typical E1 links case scenarios: An independent point-to-point E1 link between two "E1 USER PORTS" TWO groups of E1 links connected via a higher order multiplexer link. Since each SWITCH Card supports one E1 link, up to 16 E1 links, can be supported by an E1 Redundancy Switch Shelf. Two Systems are required for implementation of the 1+1 redundancy switch solution. One system must house Switch Cards configured as "MASTER" for connection at one end of the E1 links (say the near end). The other system must house Switch Cards configured as "SLAVE" for connection at the other end of the E1 links (say the far end).

Valiant Communications Limited Slide 3 E1 Automatic Protection Switching Solution Features & Highlights Provides 1+1 E1 redundancy link (active+standby) between any two complementing transmission mediums. Provides 1+1 E1 redundancy support to higher order multiplexers eg. E2,E3. System configuration & management interface through "CLI" text based commands. Transport A-bis Interface or E1’s. Provide Protection Routing / Path between BSC and BTS. Provide following interfaces at BSC / BTS Over E1 links: E1 / A-bis Interface. 10BaseT Ethernet Bridge. RS232 Async Serial (for site monitoring). NO / NC Relay / Alarm Extensions (Extend alarms Originating on dry relay contacts). Optional ms Echo - Cancellation and VQE features at BSC. Maximize mobile operator service availability and network resiliency through VCL-MegaConnect-Jr. Path - Protection enabled facility.

Valiant Communications Limited Slide 4 E1 Automatic Protection Switching Solution Features & Highlights These ensure that mission critical voice, data, control and management traffic are properly supported and maintained even during T1 / E1 backhaul facility outages.When the working link fails, the protection link becomes active. During normal Operation, VCL-MegaConnect-Jr sends duplicate traffic across both the working and dedicated protection E1 / T1 facilities while continuously maintaining the performance of both links to determine which link shall be utilized. Through the comprehensive digital access cross-connect and remote management capabilities integrated within VCL-MegaConnect-Jr, backhaul T1 / E1 facilities can be optimally groomed to reduce both Capital Expenditure and improve Network reliability. In the event of a failed or degraded T1 / E1 link, the traffic is automatically transferred from the previously working link to the duplicate protection link in accordance with the pre determined operating parameter programmed by the network operator.

Valiant Communications Limited Slide 5 E1 Automatic Protection Switching Solution Features & Highlights During normal Operation, VCL-MegaConnect-Jr APS passes independently traffic across both the working and protection E1 / T1 facilities while continuously maintaining the performance of both links to determine which to utilize for critical traffic. Traffic Protection. Alternate Facility Advantages. Service Differentiation Agreements. Increased Network Reliability Resilience. Media and Path Diversity. Remote Management.

Valiant Communications Limited Slide 6 E1 Automatic Protection Switching Solution Benefits Customer Relation Competitive Service Level Back-haul Network Technology Migration 1) User Programmable 1+1 Protection Parameters: Loss of Signal Loss of Frame Loss of Multi-Frame AIS Excessive CRC4 Violation 2) Critical Links / Critical Time-Slots Applications Providing 1+1 alternate paths between any two Transmission medium (active+standby). e.g:- Fiber / Fiber. Radio / Fiber. Radio / HDSL Fiber / HDSL etc.

Valiant Communications Limited Slide 7 E1 Automatic Protection Switching Solution Applications Diagram 1+1 REDUNDANT RING CONFIGURATION APPLICATIONS # 1

Valiant Communications Limited Slide 8 E1 Automatic Protection Switching Solution Applications Diagram TYPICAL STAR CONFIGURATION APPLICATIONS # 2

Valiant Communications Limited Slide 9 E1 Automatic Protection Switching Solution Applications Diagram Two User selectable MegaConnect options are available for reliable networks operation APPLICATIONS # 3

Valiant Communications Limited Slide 10 E1 Automatic Protection Switching Solution Applications Diagram MegaConnect (With Path Protection Switching) Normal Operation APPLICATIONS # 4

Valiant Communications Limited Slide 11 E1 Automatic Protection Switching Solution Applications Diagram MegaConnect (With Path Protection Switching) Normal Operation APPLICATIONS # 5

Valiant Communications Limited Slide 12 E1 Automatic Protection Switching Solution Applications Diagram MegaConnect (With Path Protection Switching) Working Link Fault APPLICATIONS # 6

Valiant Communications Limited Slide 13 E1 Automatic Protection Switching Solution Technical Specifications E1 Interface Number of Interfaces16 Conformity (Electrical)G.703 Frame StructureAs per ITU (CCITT) G.704 Bit Rate2048 Kbps ± 50 ppm CodeHDB3 Nominal Impedance120 W balanced Peak Voltage of a mark For 120 W Balanced interface3.0 V ± 0.3 V Peak Voltage of a space for 120 W Balanced interface0 V ± 0.3 V Nominal Pulse Width244 ns Pulse Maskas per ITU (CCITT) Rec. G.703 Output Jitter< 0.05 UI (in the frequency range of 20Hz to 100 KHz) Permissible Attenuation6 dB at 1 MHz Return Loss at: 51.2 KHz to KHz> 12dB KHz to 2048KHz> 18dB 2048KHz to 3072 KHz> 14dB Jitter ToleranceAs per ITU (CCITT) G.823 Loss and recovery of frame alignmentAs per clause 3 of ITU (CCITT) G.732

Valiant Communications Limited Slide 14 E1 Automatic Protection Switching Solution Technical Specifications Time-slot selection: ANY-TO-ANY through an internal, best byte, non-blocking TSI Switch. Clock: Internal(Stratum3 level) Loop-Timed External75 Ohms Mhz Mhz Management and Control: Serial Management Port (RS232) - COM Port 10/100 BaseT for Remote Management over a LAN. 10/100 BaseT Telnet over a TCP-IP Network. Command Language: Command Line Interface (english text commands)

Valiant Communications Limited Slide 15 E1 Automatic Protection Switching Solution Technical Specifications Specification and Regulation Compliance Meets CE requirements Complies with FCC, Part 68 and Part 15 subpart A specifications Safety - UL 1459 Issue 2 Alarm Contact Closures 1 Alarm Relay, Type - Form "C" relay, Temperature Operating0 0 C to 50 0 C Humidity 5% to 95% Non-Condensing Input Voltage Voltage-48 VDC (Range from -40 VDC to -60 VDC) Current0.104 Amp at -48 VDC

Valiant Communications Limited Slide 16 Valiant’s Products Digital Access Cross Connects - E1 / T1, E3, DS3, 10/100 BaseT Ethernet Groomers (Hi-Z Non-intrusive Hi-Impedance Monitoring) 1+1 APS (Automatic Protection Switching) Echo Canceller & Voice Quality Enhancement Solutions - E1, T1, DS3 and STM-1 E1 Drop-Insert (Add-Drop) Voice and Data Multiplexers E1, T1, E3, DS3, Ethernet Converters STM-1 Add Drop Multiplexer with Ethernet GSM Gateways - E1/T1 E1 PRI ISDN (Euro ISDN) Q.931 Multiplexers Channel Banks E2 (4 E1), 2/34 Mbps PDH Multiplexer, 34 Mbps OLTE Remote Site Monitoring Equipment E1 Automatic Protection Switching Solution

Valiant Communications Limited Slide 17 Thank you for your attention For more details visit us at our Website at E1 Automatic Protection Switching Solution U.K. Valiant Communications (UK) Ltd 1, Acton Hill Mews, Uxbridge Road, London W3 9QN, United Kingdom Website: U.S.A. Valcomm Technologies Inc Ponce de Leon, Suite 470 Coral Gables, FL United States of America Website: INDIA Valiant Communications Limited 71/1, Shivaji Marg, New Delhi , India Website: