Link Budget Tool
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Link Budget Tool
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 1 of 12
June 19, 2006
Product Tools Link Budget
Copyright Information All rights reserved June 19, 2006. The information in this document is proprietary to Redline Communications Inc. This document may not in whole or in part be copied, reproduced, or reduced to any medium without prior consent, in writing, from Redline Communications Incorporated. Contact Information
Web site: Sales Inquiries: North American Toll-free sales line International Support: Email Telephone Document ID:
Redline Communications Inc. 302 Town Centre Blvd. Markham, ON Canada L3R 0E8 http://www.redlinecommunications.com [email protected] 1-866-633-6669 [email protected] [email protected] Contact your Redline Distributor 70-00047-01-Link_Budget_Tool_20060615b.doc
Disclaimer The statements, configurations, technical data, and recommendations in this document are believed to be accurate and reliable, but are presented without express or implied warranty. Additionally, Redline makes no representations or warranties, either expressed or implied, regarding the contents of this product. Redline Communications shall not be liable for any misuse regarding this product. The information in this document is subject to change without notice.
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 2 of 12
June 19, 2006
Product Tools Link Budget
CONTENTS 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10
The Link Budget Tool.............................................................................. 4 General Description................................................................................... 4 Range Value.............................................................................................. 4 Fresnel Zone ............................................................................................. 4 Signal-to-Noise Ratio................................................................................. 6 Fade Margin .............................................................................................. 6 Availability.................................................................................................. 6 Parameter Overview.................................................................................. 7 The Link Profile Graphic ............................................................................ 9 Example: Using the Link Budget Tool ..................................................... 10 For More Information ............................................................................... 11
LIST OF FIGURES Figure 1: Fresnel Zone Obstruction....................................................................... 5 Figure 2: Fresnel Zone Radius.............................................................................. 5 Figure 3: Link Budget: Uplink/Downlink Parameters ............................................. 7 Figure 4: Link Budget Freznel Zone Graphic ........................................................ 9 Figure 5: Link Budget: Settings ............................................................................. 9 Figure 6: Link Budget For 64 QAM ¾ Code Rate ............................................... 11
LIST OF TABLES Table 1: Range Calculation ................................................................................... 4 Table 2: Fresnel Zone Calculation ........................................................................ 5 Table 3: Signal/Noise Calculation ......................................................................... 6 Table 4: Availability Versus Outage Time ............................................................. 6
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Product Tools Link Budget
1 The Link Budget Tool The Link Budget Tool is designed to help characterize the range performance of wireless systems for LOS, OLOS (optical line of sight) and NLOS conditions and various system parameters. This tool estimates the distance over which the system can operate at a desired error rate while achieving robust communication. A link is considered robust if the average error rate is less than 1 bit out of every 1000 million, expressed as 10-9, for an availability of 99.99%. Availability is described in more detail below.
1.1 General Description The Link Budget Tool provides a first-order approximation based on a generalized terrain and empirical formulas approved by governing bodies such as the IEEE and ITU. This model does not consider the details of any specific terrain profile that may impact performance, or variations arising from temperature fluctuations, cable loss tolerance, antenna alignment errors, etc. The table below describes the net data rate (after coding overhead) that can be obtained for each modulation type in an ideal propagation situation. Higher order modulation schemes require greater S/N to maintain the same BER performance. The noise in this case is defined as the noise floor of the receiver and assumes no interference from other sources.
1.2 Range Value The main path calculation for determining range performance is given as: Table 1: Range Calculation RSL = Ptx + Gtx: FSL + Grx Where: Ptx is the transmit power level in dBm Gtx is the transmit antenna gain in dB FSL is the free space loss attenuation in dB, and Grx is the receive antenna gain in dB
1.3 Fresnel Zone The FSL value is dependent on the range between the two terminals, the type of terrain over which the link is deployed, and if the link is operating line of sight (LOS), optical line of sight (OLOS) or non-LOS (NLOS). The LOS FSL calculation is based on absolutely no obstacle near the direct path. The precise method for determining the amount of clearance required for LOS uses a factor known as the Fresnel zone. 70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 4 of 12
June 19, 2006
Product Tools Link Budget
Figure 1: Fresnel Zone Obstruction
A Fresnel zone is defined as a path difference of λ/2 away from the direct path, as shown in Figure 1: Fresnel Zone Obstruction A clear LOS link assumes there are no obstacles are within 60% of the first Fresnel zone of the direct path. The diagram below illustrates OLOS conditions, where a treetop is within the first Fresnel zone, and a clear direct path exists between the antennas.
Figure 2: Fresnel Zone Radius
The formula for calculating the radius of the first Fresnel zone, as depicted in Figure 2, is given as: Table 2: Fresnel Zone Calculation
R = 72.1
D1 * D 2 (ft) f * ( D1 + D 2)
Where, - D1 and D2 are the distances from the terminals to the point of interest (in miles), and - f is the frequency (in GHz) Multiply results by 0.3048 to obtain a solution in meters.
Specific FSL formulas are required to deal with NLOS deployment. There are many NLOS calculations available from established institutions chartered with developing standardized calculations (Institute of Electrical and Electronics Engineers (IEEE) and International (Telecommunications Union (ITU)). The Link Budget Tool is designed based on these formulas; however, it is important to note that all calculations are an estimate only, with relatively large standard deviations (5 to 15 dB) depending on the actual deployment scenario and obstacle characteristics. 70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 5 of 12
June 19, 2006
Product Tools Link Budget
1.4 Signal-to-Noise Ratio Another element to consider in the path calculation is the signal to noise (S/N) ratio, which is defined as: Table 3: Signal/Noise Calculation S/N = RSL: Smin Where, Smin is the receiver sensitivity expressed in dBm.
The Smin is determined by the thermal noise generated by the amplifier and the bandwidth of the filter used in the receiver front-end. This defines the power level the receiver is sensitive enough to accurately detect the signal.
1.5 Fade Margin To ensure the link will continue to operate correctly with unexpected attenuation effects and seasonal fades, the S/N must be set higher than the S/Nmin specific for each modulation level. The difference between these two levels is called the Fade Margin (FM). Fade Margin is similar to a 'power reserve' in which extra power is designed into the Link Budget results to compensate for fades arising from seasonal climatic conditions, multipath dispersions, and shadowing effects from buildings and natural foliage. The Fade Margin is determined by the required availability. Availability is defined as the amount of time (expressed in % per year) that a link properly detects the signal (BER is less than 10-9). The table below describes the outage period per year that corresponds to the different availability values. Table 4: Availability Versus Outage Time Availability (%) 99.9 99.99 99.999 99.9999
Outage Period Per Year 8.8 hours 53 minutes 5.3 minutes 32 seconds
1.6 Availability It is recommended that a link be designed for an availability of greater than 99.99%. The Link Budget Tool automatically calculates the estimated required fade margin over distance to achieve this availability. A key advantage of Redline products is a transmission correction scheme called Automatic Repeat ReQuest (ARQ). The ARQ algorithm detects packet loss due to fading, and requests the remote-end system re-transmit the specific packets. This feature provides an equivalent link budget gain of over 5 dB, which translates directly to an improved margin. Another advantage is the multiple modulation schemes, including BPSK, QPSK, 16 QAM, and 64 QAM. Systems allow individual selection of the uplink and 70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 6 of 12
June 19, 2006
Product Tools Link Budget downlink modulation scheme. Schemes can be adjusted dynamically for changing propagation conditions, achieving optimum spectral efficiency. Higher order modulation schemes are (64 QAM) are typically deployed at reduced ranges while lower order modulation schemes (BPSK) are implemented at long distances.
1.7 Parameter Overview This section lists each of the RF parameters listed in the tool, and describes their function. The two columns are organized by path direction (not device). The left column represents the transmitter located at site A, and its receiver is located at site B. Only drop-down menu items and values displayed in blue can be entered by the user. All other values are calculated by the tool.
Figure 3: Link Budget: Uplink/Downlink Parameters
Transmitter: Select the wireless device being used for this link before entering any other technical information. Selection of a device automatically adjusts the display headings and the selections available for the transmitters, antennas, etc. Frequency: Select the operating band for this link. 70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 7 of 12
June 19, 2006
Product Tools Link Budget ODU Tx Power: Enter the (maximum) output power of the transmitter. Tx Antenna Gain: The antenna gain value is determined by the antenna selection (see Antenna Gain field in Settings). A value can be entered manually. Tx Implementation Loss: Enter the signal loss due to implementation (cables, connectors, lightning arrestors, etc). EIRP: Displays Effective Isotropic Radiated Power (EIRP). This is the apparent power transmitted towards the receiver.
Propagation Range: Enter the distance between the two ends of the link along the bore sight. Path loss: Display the predicted loss for the wireless link. This value is primarily based on the selected operating frequency, path loss model, and range.
Link Profile: Modulation / Coding Rate: Select the modulation and coding rate combination. This is used for calculating the wireless threshold and Ethernet throughput values. This field can also be calculated automatically using the Auto-Rate button (Settings); calculated results will be based on Fade Margin selection. Minimum Required CINR: Display the minimum CINR required for operating at the selected Modulation / Coding Rate. This is a calculated value. Expected Channel Throughput: Display the calculated un-coded throughput rate. This value is calculated based on device type, coding rate, and channel size. Max Unidirectional Throughput: Display the calculated maximum unidirectional Ethernet throughput. This value is based on the Expected Channel Throughput.
Receiver: Receiver Gain: This value is the Tx Antenna Gain for the opposite direction. Rx Implementation Loss: This value is the Tx Implementation Loss for the opposite direction. RSSI: Display the calculated received signal. Threshold at BER=10-6: Display the calculated minimum required RSSI for the selected modulation and coding rate combination. Fade Margin: Display the difference between the RSSI and the Threshold.
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June 19, 2006
Product Tools Link Budget
1.8 The Link Profile Graphic The link budget utility uses the link range, RF frequency, and antenna heights to estimate the path profile. For ease of interpretation, this profile is displayed in a side-view. The green arc across the bottom represents the earth-bulge due to the curvature of the earth. The link budget tool does not allow elevation data to be entered, and assumes the terrain between the antenna sites is completely flat. The grey line in the center represents the link’s bore sight, while the two outer curves represent the positive and negative 0.6 Fresnel zones. Blue lines represent an unobstructed Fresnel zone. Red lines indicate that the Freznel zone is obstruction by earth-bulge.
Figure 4: Link Budget Freznel Zone Graphic
Settings Overview: This section lists each of the utilities options and a brief description of the usage.
Figure 5: Link Budget: Settings 70-00047-01-DRAFT
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June 19, 2006
Product Tools Link Budget Antenna Height: Enter the height of each antenna. This value is used in the ERCEG path loss models. This value is also used with the link range, RF frequency to identify Fresnel zone obstruction by earth-bulge (see graphic). Antenna Gain: Select the antenna gain from the available list (based on product selection). This selection populates the Tx Antenna Gain field. If a value is entered manually, this field will be displayed as 'Custom'. Fade Margin: Select the mode for calculating fade margin. Select 'Ideal' for the default value or select 'Specified' and enter a fade margin value. Auto Rate: Click this button to automatically calculate the highest possible Modulation / Coding Rate with the given path loss. Auto Range: Click this button to automatically calculate the longest link possible using the currently configured Modulation / Coding Rate. Disable Automatic Tx Power Adjustment: Select this feature to prevent the tool from automatically adjusting Tx Power to remain within device limitations. Disable Automatic Antenna Heights: Select this feature to prevent the tool from automatically adjusting the antenna heights to prevent Fresnel zone obstruction due to earth-bulge. Calculator: Click this button to open a dialog window and enter GPS coordinates (link distance will be calculated automatically). Measurement Unites: Select metric or imperial units of measure. Path Loss Model: Select the path loss model. Press the help button (?) for a description of each model. TDM Configuration: If the selected device supports this feature, specify the number of T1 or E1 ports in use. The tool calculates and displays the required bandwidth. Channel Bandwidth: If the selected device supports this feature, select the channel bandwidth. This selection has a considerable effect on sensitivity thresholds and channel throughput.
1.9 Example: Using the Link Budget Tool This example is for a customer planning to install a new PTP AN-50 link. The link distance is 9 km, and the antennas are 2 foot flat panel antennas, with 28 dB gain. Here are the steps taken to derive a link budget: 1. Select AN50/AN30PTP as a device type 2. Select Metric for the measurement type and enter 9 into the range field 3. Select the antenna present 2 ft 4.5 deg (F) as the antenna type for each unit, or manually enter 28 for the uplink and downlink antenna gain. 4. Press the Auto Rate button to determine the best possible modulation / coding rate for this path profile
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Product Tools Link Budget
Figure 6: Link Budget For 64 QAM ¾ Code Rate
1.10
For More Information For further technical support during the upgrade procedure please contact your Redline Certified Partner or the Redline Technical Support group at 1.866.999.3537 or via email at [email protected].
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 11 of 12
June 19, 2006
302 Town Centre • Suite 100 • Markham, Ontario • Canada • L3R 0E8 www.redlinecommunications.com Copyright © 2004 Redline Communications Inc. All rights reserved. The information in this document is subject to change without notice. The statements, configurations, technical data, and recommendations in this document are believed to be accurate and reliable, but are presented without express or implied warranty. Users must take full responsibility for their applications of any products specified in this document. The information in this document is proprietary to Redline Communications Inc.
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 12 of 12
June 19, 2006
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 1 of 12
June 19, 2006
Product Tools Link Budget
Copyright Information All rights reserved June 19, 2006. The information in this document is proprietary to Redline Communications Inc. This document may not in whole or in part be copied, reproduced, or reduced to any medium without prior consent, in writing, from Redline Communications Incorporated. Contact Information
Web site: Sales Inquiries: North American Toll-free sales line International Support: Email Telephone Document ID:
Redline Communications Inc. 302 Town Centre Blvd. Markham, ON Canada L3R 0E8 http://www.redlinecommunications.com [email protected] 1-866-633-6669 [email protected] [email protected] Contact your Redline Distributor 70-00047-01-Link_Budget_Tool_20060615b.doc
Disclaimer The statements, configurations, technical data, and recommendations in this document are believed to be accurate and reliable, but are presented without express or implied warranty. Additionally, Redline makes no representations or warranties, either expressed or implied, regarding the contents of this product. Redline Communications shall not be liable for any misuse regarding this product. The information in this document is subject to change without notice.
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 2 of 12
June 19, 2006
Product Tools Link Budget
CONTENTS 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.9 1.10
The Link Budget Tool.............................................................................. 4 General Description................................................................................... 4 Range Value.............................................................................................. 4 Fresnel Zone ............................................................................................. 4 Signal-to-Noise Ratio................................................................................. 6 Fade Margin .............................................................................................. 6 Availability.................................................................................................. 6 Parameter Overview.................................................................................. 7 The Link Profile Graphic ............................................................................ 9 Example: Using the Link Budget Tool ..................................................... 10 For More Information ............................................................................... 11
LIST OF FIGURES Figure 1: Fresnel Zone Obstruction....................................................................... 5 Figure 2: Fresnel Zone Radius.............................................................................. 5 Figure 3: Link Budget: Uplink/Downlink Parameters ............................................. 7 Figure 4: Link Budget Freznel Zone Graphic ........................................................ 9 Figure 5: Link Budget: Settings ............................................................................. 9 Figure 6: Link Budget For 64 QAM ¾ Code Rate ............................................... 11
LIST OF TABLES Table 1: Range Calculation ................................................................................... 4 Table 2: Fresnel Zone Calculation ........................................................................ 5 Table 3: Signal/Noise Calculation ......................................................................... 6 Table 4: Availability Versus Outage Time ............................................................. 6
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 3 of 12
June 19, 2006
Product Tools Link Budget
1 The Link Budget Tool The Link Budget Tool is designed to help characterize the range performance of wireless systems for LOS, OLOS (optical line of sight) and NLOS conditions and various system parameters. This tool estimates the distance over which the system can operate at a desired error rate while achieving robust communication. A link is considered robust if the average error rate is less than 1 bit out of every 1000 million, expressed as 10-9, for an availability of 99.99%. Availability is described in more detail below.
1.1 General Description The Link Budget Tool provides a first-order approximation based on a generalized terrain and empirical formulas approved by governing bodies such as the IEEE and ITU. This model does not consider the details of any specific terrain profile that may impact performance, or variations arising from temperature fluctuations, cable loss tolerance, antenna alignment errors, etc. The table below describes the net data rate (after coding overhead) that can be obtained for each modulation type in an ideal propagation situation. Higher order modulation schemes require greater S/N to maintain the same BER performance. The noise in this case is defined as the noise floor of the receiver and assumes no interference from other sources.
1.2 Range Value The main path calculation for determining range performance is given as: Table 1: Range Calculation RSL = Ptx + Gtx: FSL + Grx Where: Ptx is the transmit power level in dBm Gtx is the transmit antenna gain in dB FSL is the free space loss attenuation in dB, and Grx is the receive antenna gain in dB
1.3 Fresnel Zone The FSL value is dependent on the range between the two terminals, the type of terrain over which the link is deployed, and if the link is operating line of sight (LOS), optical line of sight (OLOS) or non-LOS (NLOS). The LOS FSL calculation is based on absolutely no obstacle near the direct path. The precise method for determining the amount of clearance required for LOS uses a factor known as the Fresnel zone. 70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 4 of 12
June 19, 2006
Product Tools Link Budget
Figure 1: Fresnel Zone Obstruction
A Fresnel zone is defined as a path difference of λ/2 away from the direct path, as shown in Figure 1: Fresnel Zone Obstruction A clear LOS link assumes there are no obstacles are within 60% of the first Fresnel zone of the direct path. The diagram below illustrates OLOS conditions, where a treetop is within the first Fresnel zone, and a clear direct path exists between the antennas.
Figure 2: Fresnel Zone Radius
The formula for calculating the radius of the first Fresnel zone, as depicted in Figure 2, is given as: Table 2: Fresnel Zone Calculation
R = 72.1
D1 * D 2 (ft) f * ( D1 + D 2)
Where, - D1 and D2 are the distances from the terminals to the point of interest (in miles), and - f is the frequency (in GHz) Multiply results by 0.3048 to obtain a solution in meters.
Specific FSL formulas are required to deal with NLOS deployment. There are many NLOS calculations available from established institutions chartered with developing standardized calculations (Institute of Electrical and Electronics Engineers (IEEE) and International (Telecommunications Union (ITU)). The Link Budget Tool is designed based on these formulas; however, it is important to note that all calculations are an estimate only, with relatively large standard deviations (5 to 15 dB) depending on the actual deployment scenario and obstacle characteristics. 70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 5 of 12
June 19, 2006
Product Tools Link Budget
1.4 Signal-to-Noise Ratio Another element to consider in the path calculation is the signal to noise (S/N) ratio, which is defined as: Table 3: Signal/Noise Calculation S/N = RSL: Smin Where, Smin is the receiver sensitivity expressed in dBm.
The Smin is determined by the thermal noise generated by the amplifier and the bandwidth of the filter used in the receiver front-end. This defines the power level the receiver is sensitive enough to accurately detect the signal.
1.5 Fade Margin To ensure the link will continue to operate correctly with unexpected attenuation effects and seasonal fades, the S/N must be set higher than the S/Nmin specific for each modulation level. The difference between these two levels is called the Fade Margin (FM). Fade Margin is similar to a 'power reserve' in which extra power is designed into the Link Budget results to compensate for fades arising from seasonal climatic conditions, multipath dispersions, and shadowing effects from buildings and natural foliage. The Fade Margin is determined by the required availability. Availability is defined as the amount of time (expressed in % per year) that a link properly detects the signal (BER is less than 10-9). The table below describes the outage period per year that corresponds to the different availability values. Table 4: Availability Versus Outage Time Availability (%) 99.9 99.99 99.999 99.9999
Outage Period Per Year 8.8 hours 53 minutes 5.3 minutes 32 seconds
1.6 Availability It is recommended that a link be designed for an availability of greater than 99.99%. The Link Budget Tool automatically calculates the estimated required fade margin over distance to achieve this availability. A key advantage of Redline products is a transmission correction scheme called Automatic Repeat ReQuest (ARQ). The ARQ algorithm detects packet loss due to fading, and requests the remote-end system re-transmit the specific packets. This feature provides an equivalent link budget gain of over 5 dB, which translates directly to an improved margin. Another advantage is the multiple modulation schemes, including BPSK, QPSK, 16 QAM, and 64 QAM. Systems allow individual selection of the uplink and 70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 6 of 12
June 19, 2006
Product Tools Link Budget downlink modulation scheme. Schemes can be adjusted dynamically for changing propagation conditions, achieving optimum spectral efficiency. Higher order modulation schemes are (64 QAM) are typically deployed at reduced ranges while lower order modulation schemes (BPSK) are implemented at long distances.
1.7 Parameter Overview This section lists each of the RF parameters listed in the tool, and describes their function. The two columns are organized by path direction (not device). The left column represents the transmitter located at site A, and its receiver is located at site B. Only drop-down menu items and values displayed in blue can be entered by the user. All other values are calculated by the tool.
Figure 3: Link Budget: Uplink/Downlink Parameters
Transmitter: Select the wireless device being used for this link before entering any other technical information. Selection of a device automatically adjusts the display headings and the selections available for the transmitters, antennas, etc. Frequency: Select the operating band for this link. 70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 7 of 12
June 19, 2006
Product Tools Link Budget ODU Tx Power: Enter the (maximum) output power of the transmitter. Tx Antenna Gain: The antenna gain value is determined by the antenna selection (see Antenna Gain field in Settings). A value can be entered manually. Tx Implementation Loss: Enter the signal loss due to implementation (cables, connectors, lightning arrestors, etc). EIRP: Displays Effective Isotropic Radiated Power (EIRP). This is the apparent power transmitted towards the receiver.
Propagation Range: Enter the distance between the two ends of the link along the bore sight. Path loss: Display the predicted loss for the wireless link. This value is primarily based on the selected operating frequency, path loss model, and range.
Link Profile: Modulation / Coding Rate: Select the modulation and coding rate combination. This is used for calculating the wireless threshold and Ethernet throughput values. This field can also be calculated automatically using the Auto-Rate button (Settings); calculated results will be based on Fade Margin selection. Minimum Required CINR: Display the minimum CINR required for operating at the selected Modulation / Coding Rate. This is a calculated value. Expected Channel Throughput: Display the calculated un-coded throughput rate. This value is calculated based on device type, coding rate, and channel size. Max Unidirectional Throughput: Display the calculated maximum unidirectional Ethernet throughput. This value is based on the Expected Channel Throughput.
Receiver: Receiver Gain: This value is the Tx Antenna Gain for the opposite direction. Rx Implementation Loss: This value is the Tx Implementation Loss for the opposite direction. RSSI: Display the calculated received signal. Threshold at BER=10-6: Display the calculated minimum required RSSI for the selected modulation and coding rate combination. Fade Margin: Display the difference between the RSSI and the Threshold.
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 8 of 12
June 19, 2006
Product Tools Link Budget
1.8 The Link Profile Graphic The link budget utility uses the link range, RF frequency, and antenna heights to estimate the path profile. For ease of interpretation, this profile is displayed in a side-view. The green arc across the bottom represents the earth-bulge due to the curvature of the earth. The link budget tool does not allow elevation data to be entered, and assumes the terrain between the antenna sites is completely flat. The grey line in the center represents the link’s bore sight, while the two outer curves represent the positive and negative 0.6 Fresnel zones. Blue lines represent an unobstructed Fresnel zone. Red lines indicate that the Freznel zone is obstruction by earth-bulge.
Figure 4: Link Budget Freznel Zone Graphic
Settings Overview: This section lists each of the utilities options and a brief description of the usage.
Figure 5: Link Budget: Settings 70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 9 of 12
June 19, 2006
Product Tools Link Budget Antenna Height: Enter the height of each antenna. This value is used in the ERCEG path loss models. This value is also used with the link range, RF frequency to identify Fresnel zone obstruction by earth-bulge (see graphic). Antenna Gain: Select the antenna gain from the available list (based on product selection). This selection populates the Tx Antenna Gain field. If a value is entered manually, this field will be displayed as 'Custom'. Fade Margin: Select the mode for calculating fade margin. Select 'Ideal' for the default value or select 'Specified' and enter a fade margin value. Auto Rate: Click this button to automatically calculate the highest possible Modulation / Coding Rate with the given path loss. Auto Range: Click this button to automatically calculate the longest link possible using the currently configured Modulation / Coding Rate. Disable Automatic Tx Power Adjustment: Select this feature to prevent the tool from automatically adjusting Tx Power to remain within device limitations. Disable Automatic Antenna Heights: Select this feature to prevent the tool from automatically adjusting the antenna heights to prevent Fresnel zone obstruction due to earth-bulge. Calculator: Click this button to open a dialog window and enter GPS coordinates (link distance will be calculated automatically). Measurement Unites: Select metric or imperial units of measure. Path Loss Model: Select the path loss model. Press the help button (?) for a description of each model. TDM Configuration: If the selected device supports this feature, specify the number of T1 or E1 ports in use. The tool calculates and displays the required bandwidth. Channel Bandwidth: If the selected device supports this feature, select the channel bandwidth. This selection has a considerable effect on sensitivity thresholds and channel throughput.
1.9 Example: Using the Link Budget Tool This example is for a customer planning to install a new PTP AN-50 link. The link distance is 9 km, and the antennas are 2 foot flat panel antennas, with 28 dB gain. Here are the steps taken to derive a link budget: 1. Select AN50/AN30PTP as a device type 2. Select Metric for the measurement type and enter 9 into the range field 3. Select the antenna present 2 ft 4.5 deg (F) as the antenna type for each unit, or manually enter 28 for the uplink and downlink antenna gain. 4. Press the Auto Rate button to determine the best possible modulation / coding rate for this path profile
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 10 of 12
June 19, 2006
Product Tools Link Budget
Figure 6: Link Budget For 64 QAM ¾ Code Rate
1.10
For More Information For further technical support during the upgrade procedure please contact your Redline Certified Partner or the Redline Technical Support group at 1.866.999.3537 or via email at [email protected].
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 11 of 12
June 19, 2006
302 Town Centre • Suite 100 • Markham, Ontario • Canada • L3R 0E8 www.redlinecommunications.com Copyright © 2004 Redline Communications Inc. All rights reserved. The information in this document is subject to change without notice. The statements, configurations, technical data, and recommendations in this document are believed to be accurate and reliable, but are presented without express or implied warranty. Users must take full responsibility for their applications of any products specified in this document. The information in this document is proprietary to Redline Communications Inc.
70-00047-01-DRAFT
Proprietary Redline Communications © 2004 Page 12 of 12
June 19, 2006
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