ioWave ioLink 4 User Manual Download Page 1

02/99

PRELIMINARY

.

User Guide

Technical Reference

for

ioLink 4

Wireless System

1010 Wisconsin Avenue 

 NW 

 Suite 250 

 Washington, DC 20007

Telephone: (202) 333-9283 

 Facsimile: (202) 333-0984 

 http://www.iowave.com

Pwr

TX

RX

RF

Alm

ioLink 4 

CONSOLE

     TX                    RX

1

     TX                    RX

2

     TX                    RX

3

     TX                    RX

4

Summary of Contents for ioLink 4

Page 1: ...hnical Reference for ioLink 4 Wireless System 1010 Wisconsin Avenue NW Suite 250 Washington DC 20007 Telephone 202 333 9283 Facsimile 202 333 0984 http www iowave com Pwr TX RX RF Alm ioLink 4 CONSOLE...

Page 2: ......

Page 3: ...he system It is designed for system managers telecommunications engineers and electrical engineers those involved in hands on operation troubleshooting and monitoring of communications systems Please...

Page 4: ...2 5 2 6 2 Polarization 2 6 2 7 Typical Link Setup 2 7 2 7 1 Normal Operation 2 8 2 7 2 LCD Screen Cycling 2 8 2 8 Advanced Features 2 8 2 8 1 Performance Monitoring 2 9 2 8 2 Forward Error Correction...

Page 5: ...ted Alarms 4 5 4 5 2 RF or Far end Related Alarms 4 5 SECTION 5 TROUBLESHOOTING ALARM CONDITIONS FOR ioLink 4 5 1 5 1 Transmit LOS 5 1 5 2 LIU Not Responding 5 1 5 3 Firmware Not Responding 5 1 5 4 FE...

Page 6: ...Bit Error Rate BER for Differential Quadrature Phase Shift Keying DQPSK 2 12 Figure 3 1 Modem Unit Front Panel 3 1 Figure 3 2 Full Loopback 3 6 Figure 3 3 Far end Loopback 3 3 Figure 3 4 Source Loopba...

Page 7: ...cators 3 2 Table 3 2 Liquid Crystal Display LCD Menu Defaults 3 3 Table 3 3 Status Menu Items 3 4 Table 3 4 Configuration Menu Parameters 3 5 Table 3 5 Alarm Menu Conditions 3 8 Table 3 6 Advanced Men...

Page 8: ...with FCC regulation Part 15 Provides clear and robust communications over a range of distances Is capable of voice video and data transmissions Operates in the precertified 2 4 2 4835 GHz and 5 725 5...

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Page 10: ...ea without interference These advanced features allow the user to keep the link up and running with little effort while giving the user a powerful set of diagnostics and statistics to detect or troubl...

Page 11: ...r when the rate reaches a preset limit The user can set this alert to be triggered at a desired level to provide advance warning of potential errors and interference in the link If the link transmissi...

Page 12: ...Description The ioLink 4 indoor modem unit measures 16 7 Wide x 3 5 High x 10 4 Deep Its metal housing allows it to be rack mounted in a standard 19 equipment rack or you may place it on a flat surfac...

Page 13: ...m setups Five light emitting diodes LEDs that indicate if the unit is transmitting and receiving normally or if there is an error preventing the system from working properly Connections to the RF unit...

Page 14: ...as two TNC type jacks for connecting to the modem unit via the IF cable and an N type jack for connecting to the antenna via the RF cable Figure 2 3 RF Unit Connections The PS board contains cavity fi...

Page 15: ...re equalization without compromising the environmental seal The RF unit must be mounted so that vent immersion is not possible To help protect against lightning strikes the unit should be grounded to...

Page 16: ...k to the other is the primary factor in determining the size of the antenna In addition the environment in which you place the antennas needs to be considered in selecting the antenna size The gain of...

Page 17: ...stallation of ioLink 4 links e g a horizontal link and a vertical link Multipath fading is a situation in which the signal reflects off some object typically the ground or a building and causes interf...

Page 18: ...nit Antenna and Cables installed at each end of the line of sight link Once the link is established between the two terminals 1 The sending user s data is fed through the modem where it is multiplied...

Page 19: ...icate with the other end of the link there is a problem somewhere in the system If the Modem unit does not show the characteristics of normal operation see Troubleshooting Section 5 for help in diagno...

Page 20: ...the user to monitor link performance through the NMS as well as from the front panel Statistics for errored seconds severely errored seconds unavailable seconds and degraded minutes are automatically...

Page 21: ...block of data to predict what form the current data signal should have so that the receiver may use the redundant signal to find any errors in the original signal and correct them Depending on the na...

Page 22: ...ely by the very nature of how FEC works The BER that the user equipment sees is much better than that displayed on the Pre FEC BER menu item Although the post FEC BER cannot be exactly determined it c...

Page 23: ...re Phase Shift Keying DQPSK Note This chart does not represent the actual performance of FEC in every situation It is meant to show that the addition of FEC circuitry in the ioLink 4 improves BER as s...

Page 24: ...ic tests and alarm indicators to pinpoint performance problems By performing a few simple tests and noting the alarms the user can isolate the source of the problem for diagnosis and correction or rep...

Page 25: ...t 3 1 Front Panel Interactions The LEDs LCD and keypad are on the modem unit s front panel All system events and errors that occur are indicated on the LCD or the LEDs Because the ioLink 4 is SNMP com...

Page 26: ...only the green Pwr TX and RX LEDs are lit If the system encounters any problem the red RF and or the Alm LEDs will light up If either the RF or the Alm LED is on the LCD will show an error message Se...

Page 27: ...ZS AMI Full Loopback Off On Alarm 1 BER Threshold 2 0 E 7 Signal Level xx T1 Data Cable 133 266 399 533 655 Far end Loopback Off On Alarm 2 BER Interval 100 s Pre FEC BER x x E x TX Code 1 2 3 4 Sourc...

Page 28: ...his is the rate of bit errors that are received from the link before correction by the Forward Error Correction FEC circuitry In usual operation the FEC circuitry corrects most of the bit errors so th...

Page 29: ...y present for T1 modems TX Code RX Code There are four choices for the PN pseudo random noise sequence used to spread and de spread the signal For the link the RX code for each modem must match the TX...

Page 30: ...es on the back of the modem unit to read out the conditions of the test The BERT can be used to provide bit streams for performing a test or it can be used simply to test the signal already present in...

Page 31: ...pback Selecting YES for this test mode places the modem into a loopback mode at the line interface chip In this mode the data from the user device connected to the DSX or G 703 interface is looped bac...

Page 32: ...ction to be taken Table 3 5 Alarm Menu Conditions Near end Related Alarms Transmit LOS LIU not Responding Firmware not Responding This alarm is caused by a loss of signal from the user s device into t...

Page 33: ...this is the only alarm condition it is usually an indication that there is a problem with the far end modem This alarm is caused by a low value of signal power being received by the RF unit In additi...

Page 34: ...Threshold the ioLink begins timing If the Pre FEC BER falls back below the BER Threshold the timer is reset to zero Otherwise the timer continues until the specified interval is surpassed which then c...

Page 35: ...o determine whether the line interface and forward error correction sections of the modem are operating correctly b LIU Loopback There are three loopback modes available from this menu item all of whi...

Page 36: ...embedded into the modem unit This feature allows user SNMP software to interface with the ioWave SNMP compliant agent The Revision 1 1 1 version of the embedded software includes a serial interface t...

Page 37: ...re are fuses diodes and transformers between these connectors and the circuitry of the modem unit to protect the DS1 input device against voltage and current surges Note The termination impedance is s...

Page 38: ...g EIA interface AC inlet and a rocker on off switch A standard grounded power cable is sufficient for connecting to an AC power source e g any common wall mounted receptacle As indicated in the Techni...

Page 39: ...4 V DC offset on the TX cable supplies power to the RF Unit When the Modem Unit is on the center pin of the TX connector is at 48 V relative to the grounded outer conductor Because of this when config...

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Page 41: ...ard entry of SNMP type Set Get and Next commands and then communicates with the agent via UDP packets is available from ioWave 4 1 Functionality The agent is built to conform to the DS1 Management Inf...

Page 42: ...dB Jitter Attenuation For input devices with a significant amount of noise the line interface unit may provide jitter attenuation Jitter attenuation is provided by an elastic store ES which clocks in...

Page 43: ...ar end modem Input from the near end DSX or G 703 interface is ignored By setting the far end modem into this mode a test of the complete link may be made 2 Remote The data from the user device connec...

Page 44: ...of bit errors that are received from the link In usual operation the FEC circuitry corrects most of the bit errors so that the error rate of the data sent to the user s equipment is smaller than this...

Page 45: ...ing This alarm indicates an error with the communication between the control processor and the firmware controlling the FEC and spreading chips This is generally a fatal alarm condition in that it ind...

Page 46: ...LED to be extinguished If this alarm condition exists and RX Low Signal Power does not exist the likely causes of this alarm condition are either that the far end of the link is turned off or has fail...

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Page 48: ...er going through the troubleshooting steps please contact ioWave Technical Support Singular Alarm Conditions 5 1 Transmit LOS No data into DSX or G 703 1 Check connection to CPE a Verify that the CPE...

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Page 50: ...trees or changes in the landscape For example if a stand of trees between the two antennas grows enough to sufficiently block the Fresnel zone the Pre FEC BER will increase Also if that same stand of...

Page 51: ...far ends of the link 4 Check that the IF cable is connected properly and not damaged 5 Verify that the far end Modem unit is on and operating normally If any alarm conditions exist troubleshoot them...

Page 52: ...ioLink 4 PRELIMINARY Customer Support 202 333 7031 5 4 Figure 5 1 Received Signal Strength Indicator RSSI Voltage Conversion RSSI Average Data 120 110 100 90 80 70 60 50 40 30 20 10 0 0 50 0 00 0 50...

Page 53: ...t as well there will most likely be an RX Low Signal Power or RX Low Symbol Power alarm as well see above 2 Check the status of the Modem unit at the far end Make sure it is powered on and in normal o...

Page 54: ...12 bit orthogonal Walsh Hadamard Code Length TBD Number of Stored Codes TBD Forward Error Correction Viterbi mode _ rate encoding 3 bit soft decision receive decoding Receiver Receive Level TBD dBm n...

Page 55: ...1 RJ 48C Female 100 ohms twisted pair cable x4 G 703 4x E1 BNC x2 Female 75 ohms coaxial cable x4 Monitor and Control Designed to operate reliably even under marginal link conditions Remote RS232 SNMP...

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Page 57: ...arge per second Amplitude The magnitude of a waveform when measured from the mid point to the peak of the wave Analog A signal in the form of a continuously varying quantity such as voltage frequency...

Page 58: ...nary A Base 2 numbering system A binary code consists of elements represented by two distinct conditions such as 0 1 on off or mark space This numbering system is the basis for digital code Bipolar ei...

Page 59: ...ent CPE Any equipment which is located at the customer site Usually in reference to those that are connected to a network D dBm dB relative to 1 milliwatt dBw dB relative to 1 watt Decibel dB The stan...

Page 60: ...on the antenna is pointed Equivalent Isotropically Radiated Power EIRP The product of the power supplied to the antenna and its gain in a given direction relative to an isotropic antenna ESD Electro S...

Page 61: ...ansmitter or antenna H Hertz Hz A unit of measurement equal to one cycle per second Hexadecimal Hex or H A Base 16 numbering system High Density Bipolar Three HDB3 A line interface standard similar to...

Page 62: ...rface Unit LIU The first unit inside the modem units encountered by signals from the user Line Of Sight radio LOS Condition whereby the antennas of a given link have a sufficient path for communicatio...

Page 63: ...early polarized signals more than circularly polarized signals MUltipleXer MUX A device that allows the simultaneous transmission of two or more signals over one transmission path N Network Two or mor...

Page 64: ...uced by a transmitter Measured in dBm Propagation The transmission of a wave along a given path through a medium Pseudo random Noise code PN code A high rate digital code that mimics random noise like...

Page 65: ...hod of encoding with a PN code a digital signal in a transmitter so as to spread it over a wide range of frequencies so that the average signal power is close to the noise floor The same code is known...

Page 66: ...nsmission User Datagram Packets UDP A connectionless protocol that runs on top of IP networks It offers a direct way to send and receive datagrams over the network but provides very little error recov...

Page 67: ...e must be performed by authorized ioWave personnel or those persons properly trained and authorized to do such procedures ioWave is not responsible for any damages incidental or otherwise in connectio...

Page 68: ...t during the warranty period Buyer must return item freight pre paid to the ioWave repair facility for repair or replacement Proper authorization from ioWave to return products under this warranty mus...

Page 69: ...laced in Any alterations in structures on the site where the ioWave equipment is installed may void any warranties that exist for the structure e g drilling holes in walls floors or ceilings may void...

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