NEC ipasolink 400 User manual

NEC IPASOLINK 400
INSTALLATION AND PROVISIONING
© Pekka Linna NEC Finland Oy 2012

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CONTENTS
INTRODUCTION ......................................................................................................................6
PRODUCT DESCRIPTION.....................................................................................................6
IPASOLINK 400........................................................................................................................7
COMPATIBLE OUTDOOR UNITS........................................................................................8
NHG .....................................................................................................................................8
NHG2 .....................................................................................................................................8
IHG .....................................................................................................................................9
BLOCK DIAGRAMS................................................................................................................9
AVAILABLE CONFIGURATIONS.......................................................................................11
UNPROTECTED HOP.......................................................................................................11
PROTECTED CONFIGURATIONS .................................................................................11
ETHERNET PROTECTION USING 2+0 OR XPIC 1+0..............................................................11
RADIO TRAFFIC AGGREGATION.............................................................................................11
CONFIGURATION DIAGRAMS .................................................................................................12
ASYMMETRICAL HOPS...........................................................................................................15
EXTERNAL CONNECTION SPEED AND RADIO PATH CAPACITY..........................15
IPASOLINK CAPACITY.............................................................................................................16
QOS AND OVERPROVISIONING.......................................................................................18
ADAPTIVE MODULATION...................................................................................................18
MAIN SPECIFICATIONS ......................................................................................................20
IDU CONFIGURATIONS.......................................................................................................22
PDH-INTERFACES............................................................................................................24
MANAGEMENT AND AUXILIARY INTERFACES ........................................................................24

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INDOOR UNIT CONFIGURATIONS...................................................................................25
ORDERING CODES..............................................................................................................26
PREINSTALLED LICENSES ...............................................................................................26
SAFETY ISSUES....................................................................................................................26
OPEN WAVEGUIDE AND OPTICAL CONNECTORS ..................................................................26
AVOID THE FRONT OF THE ANTENNA....................................................................................26
RADIATION MONITORING DEVICES............................................................................27
SAFETY DISTANCE FOR THE PUBLIC EXPOSURE..................................................27
INDOOR UNIT INSTALLATION..........................................................................................28
VENTILATION.....................................................................................................................28
ENVIRONMENTAL REQUIREMENTS........................................................................................28
POWER CONNECTION............................................................................................................29
ASSEMBLING THE POWER CABLE..............................................................................29
ETHERNET CABLE CONNECTIONS.............................................................................30
PDH CONNECTIONS...............................................................................................................30
ODU INSTALLATION............................................................................................................30
6GHZ ODUWITH STANDARDWAVEGUIDE...............................................................31
SEPARATE INSTALLATION OF 7AND 13 GHZ DIRECT MOUNT ODU......................................32
DIRECT MOUNT INSTALLATION...................................................................................32
ODU CABLE INSTALLATION....................................................................................................34
CABLE CONNECTORS.....................................................................................................35
GROUNDING......................................................................................................................35
Grounding outside .................................................................................................................................... 35
Grounding in the shelter .......................................................................................................................... 36
Suitable grounding connectors............................................................................................................... 36

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IDU AND CABLE LABELLING ...................................................................................................36
OVERVOLTAGE PROTECTION................................................................................................36
LOCAL MANAGEMENT.......................................................................................................37
MANAGEMENT TOOL.......................................................................................................37
RECOMMENDED BROWSER...................................................................................................37
LOCAL CONNECTION .............................................................................................................37
REMOTE LOGIN USING THE BROWSER..................................................................................38
LOGINWINDOW................................................................................................................38
MAIN PAGE –MENU AND CURRENT STATUS.........................................................................39
NAMING OF THE IDU AND MODEMS .......................................................................................39
BASIC SETTINGS..................................................................................................................39
PROVISIONING CLEAR....................................................................................................40
NETWORK MANAGEMENT (NMS) SETTINGS............................................................47
MODEM SETTINGS...........................................................................................................51
SYNCHRONIZATION SETTING ...............................................................................................52
DATE AND TIME SETTING.......................................................................................................55
NETWORK MANAGEMENT SECURITY SETTINGS ...................................................................56
ANTENNA ALIGNMENT.......................................................................................................61
MANAGEMENT NETWORK ................................................................................................63
DCN OVER PDH/SDH..............................................................................................................65
MANAGEMENT USING METRO ETHERNET VPLS SERVICE..................................65
PROVISIONING PDH............................................................................................................66
ETHERNET SETTINGS ........................................................................................................69
VLAN SETTINGS .....................................................................................................................70
BRIDGE MODES (802.1Q AND 802.1AD)..............................................................................72

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SAMPLE VLAN SETTINGS.......................................................................................................73
QOS SETTINGS.....................................................................................................................76
TRAFFIC CLASSIFICATION PRINCIPLES....................................................................76
SAMPLE QOS POLICY......................................................................................................79
QOS SETTINGS –CLASSIFY AND INGRESS POLICING..........................................80
PORT QOS SETTINGS.............................................................................................................82
QOS SETTINGS SUMMARY.....................................................................................................84
COPYING SETTINGS FROM ONE IDU TO ANOTHER..................................................85
PRECONFIGURATION FILES.............................................................................................90
KNOWN PROBLEMS............................................................................................................91
APPENDIX A. RECEIVER THRESHOLD DATA..............................................................92
APPENDIX B. MC-A4/16E1-A MDR68-CONNECTOR PIN LAYOUT..........................95
APPENDIX C. MC-A4 D-SUB-44 CONNECTOR PIN LAYOUT...................................96
APPENDIX D. QUICK INSTALLATION GUIDE/CHECK LIST ......................................97
Version 2.4 2012-09-20

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INTRODUCTION
This document describes the installation and provisioning of NEC iPasolink 400 microwave transmission
equipment. The information is based on the IDU firmware version 3.00.37. Additional information is
available in the manual iPasolink 400 Installation, Operation and Maintenance (NWD-115474-05E).
iPasolink 200 and iPasolink 1000 are very similar; however, there are some differences due to hardware
configurations. Reference is made to the appropriate equipment manuals.
Appendix D contains a quick provisioning guide. The quick guide is based on the configuration files that
have to be copied to the equipment before using the quick setup. The configuration files have to be
customised for each customer’s basic HW configuration. Rebooting of the equipment with traffic
interruption will take place when the configuration file is copied to the equipment.
PRODUCT DESCRIPTION
The microwave transmission family (iPasolink 100/200, 400 and 1000) enables full duplex wireless
transmission between two modems at a rate of over 400 Mbit/s per direction. With XPIC and radio channel
aggregation, over 800 Mbit/s per radio channel can be achived.
The interfaces are based on the Ethernet, PDH and SDH standards.
Frequency division duplex is used. A pair of channels separated by certain duplex spacing is required.
iPasolink uses licensed frequency bands. The frequency administration provides interference-free channels
to different operators based on frequency planning: transmitter powers and antenna sizes etc are
specified. Alternatively, in some countries, the operator may be given a block allocation of spectrum and
the operator is then responsible for the proper frequency planning inside the block. In any case, the correct
operation is only possible with proper frequency planning so that adequate signal-to-interference margin is
available. Moreover, the microwave hop has to be planned according to current ITU-R methods in order to
ensure sufficient margin against fading.
NEC iPasolink uses the traditional split mount installation method: indoor unit (IDU), coaxial cable, outdoor
unit (ODU) and antenna. Different products of the iPasolink 100/200/400/1000 family may interface over
the air with certain limitations regarding maximum modulation. Fully outdoor versions (iPasolink AX, SX and
EX) are also available but are not over-the-air compatible with iPasolink 100, 200, 400 or 1000.
The indoor unit contains the baseband interfaces (nxE1, STM-1, FE or GbE) as well as modems, a power
supply (or supplies) and a control unit with NMS interfaces. The interconnecting cable uses intermediate
frequencies below 400 MHz for the data and control signals. It feeds the power to the outdoor unit at -48

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V. The frequency bands available cover the standard bands 6 to 42 GHz. Microwave signals do not
penetrate buildings, vegetation or terrain nor bend around obstacles. Therefore the antenna has to be
placed on top of a tall building or on a tall tower or mast in order to provide free line-of-sight connection to
the opposite end.
IPASOLINK 400
This guide is based on the middle-sized member of the family, the iPasolink 400. It may contain up to four
(4) modems. Each modem can provide Ethernet L2 capacity 10 to 400 Mbit/s or PDH/SDH capacity up to
152 x E1 or 2 x STM-1 or various combinations. The actual capacity depends on the available channel width
and available signal to noise/interference ratio and the fade margin required to fulfil the availability targets.
In the most basic configuration only one of the four slots contains a modem. The main card has always
FE/GbE and E1 interfaces. The other slots may contain additional GbE, SDH or E1 interfaces or modems. In
addition, TDM over packet (PWE), Synchronous Ethernet etc. options are available.
The highest capacities (400 Mbit/s) require access to a frequency band with 55 to 60 MHz channel spacing,
typically such channels are available in the upper 6 GHz, 18 GHz, 32 GHz or 38 GHz bands. On such bands
where the maximum spacing is only 27.5 or 28 MHz, the maximum capacity per modem is limited to about
200 Mbit/s. If necessary, two modems can share the same channel by using orthogonal polarizations and
XPIC (cross-polarization interference canceller). In such a setup the maximum combined capacity is about
400 Mbit/s (27.5 or 28 MHz channels) or about 800 Mbit/s (55 or 56 MHz channels).
The element management connection is based on Ethernet/IP transmission. All elements should be
connected to an EMS (PNMSj or MS5000). Within each iPasolink cluster the management traffic is carried
internally and separated from the customer traffic. A dedicated gateway connection (NMS port) to the
management data communication network (DCN) is typically used at the “root” element of the cluster.
Another solution is to use a traffic interface at the root element (in-band connection to root element).
Figure 1. iPasolink 400 indoor unit (IDU).

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In the unit in Fig. 1 two modems (left) and a GbE interface card (right) have been installed. The unused slot
is covered by a blank cover. In the lower part are (from the left): the main card, a power supply, an unused
power supply slot and the fan unit.
COMPATIBLE OUTDOOR UNITS
Figure 2. Compatible outdoor units.
Indoor units: IHG is the latest version, silver coloured. NHG2 is white on the higher bands and beige on the
lowers bands whereas the NHG and the 6 to 11 GHz NGH2 look identical.
Any two IDUs belonging to the iPasolink 100/200/400/1000 family can be connected over the air. Note that
iPasolink IDU cannot interface to a previous generation (e.g. PASOLINK NEO) IDU. However, older
generation ODUs can be reused with iPasolink IDUs. There are certain limitations presented below.
NHG
NHG does not support 256QAM or higher modulations; only 128QAM and lower modulations formats are
guaranteed to work properly. When used with iPasolink IDU the FW version of the NHG ODU has to be 3.50
or later. This upgraded ODU will not work with a Pasolink NEO IDU any more - unless FW is downgraded
back to 3.50.
NHG2
NHG2 FW 4.06 works only with an iPasolink IDU. Earlier FW versions than 4.06 work only with Pasolink NEO
IDU. The recommended NHG2 FW version is 5.08 or later, which are compatible with both Pasolink NEO

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and iPasolink indoor units. NHG2 upgrade to level 5.08 from lower level than 4.90.0 is a two-step upgrade:
to level 4.90.0 first and then to level 5.08 or later.
IHG
IHG FW version should be 5.08 or later. IHG will then work with iPasolink and PASOLINK NEO.
BLOCK DIAGRAMS
The block diagram of iPasolink 400 Indoor Unit (IDU) is presented in Figure 3. The Outdoor Unit (ODU) is
described in Figure 4.
The IDU main card has a separate TDM switch and a packet network L2 switch. It supports natively both
circuit-switched TDM as well as packet-switched Ethernet transport modes. In addition the equipment
supports the ”TDM-over-Ethernet” mode when equipped with the PWE option.
The modulator part of the modem generates an intermediate frequency signal. It is modulated by the
digital baseband signals and sent up to the ODU. The demodulator part demodulates the intermediate
frequency signal coming down from the ODU.
The demodulator includes an adaptive equalizer which repairs the linear distortions (poor amplitude and
phase response of the channel) caused by multipath fading. It also includes a FEC (Forward Error Correction
code) which is able to correct bit errors even very close to the threshold receive level. The system is almost
error-free until very close to the threshold and the transition to outage is within a couple of dB.
It is possible to equip the iPasolink 400 and 1000 IDUs with two redundant power supplies. Interruption of
one -48V supply voltage or a fault in one power supply unit will not cause any traffic interruption. Note:
iPasolink 100/200 has two independent connections to external -48V voltage but does not contain a
redundant power supply unit.

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Figure 3. iPasolink 400 IDU, block diagram.
Figure 4. IHG ODU, block diagram.
The Outdoor Unit (ODU) generates the final microwave signal using the IF signal from the IDU by
upconverting it one or two times (MIX). The output of the mixer is band-pass filtered (BPF) in order to
remove the unwanted mixing products and then power amplified (PA). In the receive direction there is a
Low Noise Amplifier (LNA) and a mixer/filter which generates the receive direction IF signal. The local
oscillator (LO) frequencies are synthesized and controlled by the Control unit (CTRL). Transmitter output
power is fine-controlled automatically according to the modulation used and optionally based on the
remote end received power (Automatic Transmit Power Control, ATPC).
Both the modem in the IDU and the ODU contain a duplexer (DUP, MPX) which combines the different
directions of transmission to the same cable connector. The ODU power supply uses the DC voltage (-48V)

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connected to the single coaxial cable centre conductor. The ODU can be mounted up to 500 metres from
the IDU, when a high-quality (e.g. ½ inch low-loss) coaxial cable is used.
AVAILABLE CONFIGURATIONS
UNPROTECTED HOP
The most basic configuration is a 1+0 or unprotected hop between a pair of modems. A single iPasolink 400
IDU can have up to four (4) 1+0 connections to separate sites. In this maximum configuration four ODUs,
four antennas and four coaxial cables are needed together with one IDU and four modems.
PROTECTED CONFIGUR ATIONS
If the requirement for the service restoration time after a failure is very strict, there is no time to go to the
site to replace the failed unit. In some cases the Service Level Agreement (SLA) does not allow any service
interruption caused by equipment failures. In such cases a 1+1 protected hop can be used. Both
transmitters may be transmitting always, each using a separate channel (frequency diversity, twin path).
Alternatively the spare transmitter is activated and the main transmitter muted only during a transmitter
failure (hot standby). In both solutions the receivers and demodulators are always activated and the IDU
will select the better (less bit errors) signal for processing.
The reliability (MTBF) of iPasolink is very high, which means that the traffic MTBF of the 1+1-solution is
extremely high, provided that the first fault is repaired within a reasonable time (within a few days). The
main disadvantage - in addition to double equipment cost - of the 1+1-solution is that the number of
equipment faults will double compared to the 1+0 solution. As an expample: if the equipment MTBF of a
1+0 hop is 100 years, then the MTBF of a 1+1 hop is approximately 50 years. But the traffic MTBF of a 1+1
hop could be perhaps 1000 years, however, depending on the fault repair time. Another disadvantage of
the 1+1 twin path solution is that only 50% of available capacity per MHz is in actual use.
ETHERNET PROTECTION USING 2+0 OR XPIC 1+0
A more cost efficient solution to protect Ethernet connections is to use 2+0 (or XPIC 1+0) on the same hop.
The traffic is then distributed between two modems and ODUs. The normal capacity could be as high as
800 Mbit/s. In case of a failure of an ODU, as an example, the traffic may still use the other ODU at 400
Mbit/s.
It is possible to use a dual-polarised antenna with XPIC (Fig. 7). It should be noted that the partial
equipment protection using “1+0 XPIC”is not fully automatic: the non-functional side transmitter has to be
muted manually in order to operate the remaining side at full speed.
RADIO TRAFFIC AGGREGATION
Radio traffic aggregation (RTA) to a single external Ethernet external interface can be done at L2 or L1 level.

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When using L2 aggregation, a single “stream” is not distributed to the two radio paths due to the known
limitation of the standard LAG method. Several streams (e.g. different MAC DA or SA) are needed in order
to use the full capacity.
The more advanced NEC proprietary L1 aggregation (Physical RTA, PRTA) method will create a genuine
combined Ethernet port towards the air and even a single Ethernet stream can use the full capacity.
Modem versions supporting L1 aggregation PRTA: see Table 6 below (page 24).
CONFIGURATION DIAGRAMS
Figures 5 to 7 present the available configurations for iPasolink.
Figure 5. Basic configurations
From top to bottom, Figure 5 shows first a basic 1+0 hop, then a 1+1 Hot Standby (HS) and finally a three-
antenna Space Diversity (SD) solution combined with HS protection.
A single antenna is used with a hybrid (HYB). The hybrid will cause some extra attenuation in the radio
path, with a corresponding loss in the fade margin and increase in the outage time caused by fading. The
three-antenna SD solution is thus less effective than a genuine SD solution. In addition the space diversity
in the right-to-left direction is based on transmitter switching, which is not hitless (bit errors when
switching over).

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Figure 6. Additional configurations.
Figure 6 shows on the top a HS/SD solution using four antennas per hop. This is the best solution for long
hops: no loss of fade margin and switching is hitless in both directions.
The middle solution is 2+0, i.e. two working channels and no protection channel. However, considering
Ethernet traffic, 2+0 has some protection against a single equipment failure. Two separate radio channels
are required and when properly configured, when a fault occurs in an ODU or modem, L2 or L1 aggregated
packet traffic is automatically rerouted to the remaining working channel. Half of the packet capacity is still
available when one channel is faulty.
The bottom configuration in Fig. 6 is an aggregation node solution: separate sites connected to a single IDU
and a single Ethernet connector. One or more radio channels will be needed depending on the angular
spacing of antenna directions. In principle 4+0 without XPIC can be even used on a single hop but then four
radio channels are needed.
It is possible to use less radio channels on the same hop using XPIC and crossed polarizations (Figure 7
below). The modems are interconnected using XPIC cables. The system calculates the original signals using
all available information, i.e. both IF signals are connected to both modems.

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Figure 7. XPIC configurations.
Figure 7, top, shows a basic XPIC 1+0 (could be called XPIC 2+0 as well). It uses a single channel pair, two
polarizations and four modems per hop over a single antenna per site. Double capacity is achieved without
using any extra spectrum. Note: 1+0 XPIC partial protection for aggregated packet traffic is not automatic.
When a fault occurs preventing the use of XPIC, the interfering transmitter has to be manually muted
(either locally or remotely) in order to remove the interference and allow maximum speed operation of the
remaining modem.

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This solution uses a dual-polarized antenna with an integrated Orthomode Transducer (OMT). Four ODUs
can be attached directly to a single antenna without any cables or waveguides between the antenna and
the ODU.
The middle part of Figure 7 shows a 1+1 XPIC solution: it is protected against modem, cable and ODU faults.
A single fault will not affect the traffic capacity. This solution uses a hybrid connection between antenna
and the ODUs to connect two ODUs at a different frequency to the same antenna port.
The last solution with separate IDUs is the most complex but also best protected against equipment
failures. An external Ethernet switch is required at each end for traffic rerouting. Switching or load
balancing can be based on Link Loss Forwarding (LLF) or Link Aggregation Group (LAG). This solution
protects against practically all IDU failures.
XPIC requires the use of dual-polarized antennas. If an XPIC upgrade is anticipated, a dual-polarized
antenna with an integral OMT for two or four ODUs may be installed initially. The unused ports are
protected by blanking plates and gaskets and the empty fixing screw holes should be fitted with a screw,
washer and rubber washer in order to keep the OMT interface clean and ready for ODU and cable
installation later.
ASYMMETRICAL HOPS
Often the two ends of the hop are identical. But it is possible to use a different IDU (e.g. iPasolink 400 or
1000 in the aggregation node and iPasolink 200 or 100 in the remote end). The interface type can be
different (e.g. FE in the remote IDUs, optical GE in the aggregation IDU). Several Ethernet ports may be
used in one end and aggregated to a single port in the other end.
Similarly, it is possible to aggregate n x E1 interfaces of a long chain of links to a single STM-1 interface at
the trunk network node. In other words, the E1 channels of a modem can be cross-connected to the 16 x E1
connector of the main card, to another modem or to a time slot in the STM-1 connection.
EXTERNAL CONNECTION SPEED AND RADIO PATH CAPACITY
The total L1 capacity of the external Ethernet interfaces of an IDU may well exceed the available radio path
capacity. This is normal, of course. The type and speed of the external interface is selected based on the
external requirements. It is the sum of the L2 traffic carried by the interfaces at a given moment (plus the
available buffering capacity in iPasolink) that must fit in the radio channel. Note that iPasolink only
transmits the L2 bytes over the air. Constant L1 overhead bytes are removed and restored by the system
(L1 compression). For this reason the corresponding external L1 speed is always greater than the L2
capacity needed to transmit the information at the air interface (Figure 8).

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Figure 8. Typical Ethernet frame. Preamble, Start of frame delimiter and Interframe gap (L1 overhead) are never
transmitted over the air. Optionally also MAC destination and Mac source adresses may be compressed.
The highlighted octets (20 octets) in Figure 8 are removed and instead three octets are added for internal
purposes. The net compression is 17 octets per frame. The effect of compression is only significant when
frames are very short (in the order of 64 to 512 octets). There is no compression gain at all when the
average frame size is large (e.g. 1500 octets/frame).
Optionally L2 layer compression of MAC addresses can be used. This will remove almost 12 octets,
assuming that only a very few MAC addresses are in use at a given time. In the same way as for L1
compression, removing some octets has no significance when the average frame size is large.
When talking about link capacity, it is always recommended to define if it is measured at the external
interface at L1 level (including and counting all octets) or if it is the L2 capacity. The difference is only
significant when small frames are used for the measurement.
IPASOLINK CAPACITY
Table 1 shows examples of maximum capacities available in iPasolink currently.
Modulation
Channel
Spacing
(MHz)
Frame size
(L2 octets)
Radio capacity L2
+ internal (Mbit/s)
External L1
capacity
occupied
(Mbit/s)
L2 capacity
transmitted
(Mbit/s)
256QAM
56
64
367
460
350
256QAM
56
1500
367
371
366
256QAM
56
8000
367
367
367
512QAM
56
64
412
517
394
512QAM
56
1500
412
417
412
512QAM
56
8000
412
413
412
Table 1. Example capacities at various frame sizes (L2 MAC compression not used)
The above figures show how the L1 capacity required at the external interface is much larger than the radio
capacity used for small frames. On the other hand, the available L2 radio capacity is best used with large
frames (internal use of three octets per frame becomes negligible).
For a reference, Table 2 shows the standard 1000 Mbit/s GbE L2 speeds for the same frame sizes as above.
As always, the available L2 speed depends on the frame size and the L1/L2 difference vanishes with large
frames.

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Frame size (L2 octets)
L1 capacity
(Mbit/s)
L2 capacity
(Mbit/s)
64
1000
761,9
1500
1000
986,8
8000
1000
997,5
Table 2. GbE interface L2 capacity also depends on the frame size.
If the average frame size were only 64 octets, there would be a problem fitting the 2+0 maximum capacity
at 56 MHz and 512QAM into a single GbE interface. This is because the total L2 speed is 2 x 394 = 788M,
which would need over 1 Gbit/s at interface L1 speed (2 x 517 = 1034M). In other words two modems
could send more packets than a single GbE interface can handle.
In practise the average packet size is always much larger than 64 octets, perhaps 500-1000 octets, and then
the GbE interface can handle all the packets delivered by two modems.
The compression can become an interpretation problem when measuring the link capacity with the
smallest frame size. If the capacity is defined using the smallest frames only, that capacity cannot be
achieved with real traffic and a larger average frame size. This may cause SLA problems between the
operator and the end customer. It is recommended that the capacity is defined and measured using the
largest possible frames which will remove the L1/L2 difference. Then the real capacity achievable is always
slightly larger than the measured one.
Table 3 shows iPasolink radio capacities with each available modulation and channel spacing. This value is
practically identical with the L1 and L2 capacity when the average frame size is 1500 octets or larger.
(1024QAM and 2048QAM are preliminary values).
Radio capacity (Mbit/s)
Modulation
Channel spacing
7MHz
14MHz
28MHz
56MHz
QPSK
10
22
45
91
16QAM
22
45
91
183
32QAM
27
56
113
228
64QAM
33
67
136
274
128QAM
39
79
159
320
256QAM
45
90
182
366
512QAM
-
-
205
412
(1024QAM)
-
-
(228)
(458)
(2048QAM)
-
-
(251)
(504)
Table 3. iPasolink radio capacity.

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QOS AND OVERPROVISIONING
If the traffic coming to the IDU is very bursty and time-variable, so called “overprovisioning”(or
“overbooking”) of the radio is a possible method for cost savings. Due to the statistical variation and the
fact that the traffic peaks seldom occur simultaneously. The combined traffic has a peak value less than the
sum of the peak values of contributing interfaces.
The random nature of real traffic will sometimes cause the radio channel to be overloaded. This will happen
more often when unfavourable weather conditions force the use of lower modulation formats (when
adaptive modulation, AMR, is used). Overprovisioning must take into account overloading conditions and
the priority of frames must be considered. Obviously less important traffic and non-realtime traffic should
be dropped first.
iPasolink can use statistical multiplexing very effectively because it understands the incoming frame
priority, it may shape the traffic and there is a queuing mechanism to the radio path.
The operator should design the radio capacity based on the traffic statistics and SLA requirements and
define the QoS parameters required in the radio.
ADAPTIVE MODULATION
As was the case already with the previous generation PASOLINK NEO HP AMR, iPasolink may use adaptive
modulation (AMR) which improves the reliability of high priority traffic or alternatively increases the
available capacity for lower priority traffic during majority of time. AMR is especially important when using
high modulation formats with lower sensitivity and lower fade margin resulting in higher equipment costs
such as larger antenna. With AMR different traffic classes may have a different fade margin and availability.
Figure 9. Adaptive modulation.
An example: the most cost-efficient solution could be that a nominally 366 Mbit/s hop is designed for
99,9993% availability for 16QAM 183 Mbit/s for “Business Critical and Real Time” traffic. For Best Effort
traffic, the full 366 Mbit/s 256QAM availability could be 99,993% of time. In this manner, the last 25% of
traffic (e.g. Real Time) would have practically 100% availability (91 Mbit/s QPSK). This kind of availability

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design is of course based on the empirical rain and multipath fading models for the average worst month.
No real guarantee for the availability due to weather conditions can be given, but statistically the designed
hops will meet the targets.
A more expensive solution would be to design the hop for 99,999% availability for the full 256QAM 366
Mbit/s. This would mean using larger antennas and/or shorter hop lengths (i.e. additional CAPEX). The
adaptive modulation would then ensure that high priority traffic at lower capacity would have much better
availability.
It is crucial that the hop attenuation after aligning the antenna is correct when compared to the fade
margin calculation. If the designed fade margin is not available, the availability for the various traffic
classes cannot be achieved.

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MAIN SPECIFICATIONS
The following tables present the main technical specifications of the iPasolink 400 equipment. Some
performance data are given in Appendix A.
PDH
SDH
LAN
ODU frequency bands
6, 7, 8, 10, 11, 13, 15, 18, 23, 26, 28, 32, 38, 42 GHz
Capacity per modem (*512QAM
Modem HW 2.00 and later)

152 x E1 (256QAM)
1x155 Mbit/s tai
2x155 Mbit/s
< 412 Mbit/s*
External line signals and
interfaces
E1 (ITU-T G.703)
75/120 ohms
MDR-68 female (16xE1)
(See Appendix B and C).
S-1.1/L-1.1 (ITU-T
G.957): LC
ITU-T G.703: DIN
1.0/2.3
10/100/1000 Base-
T(X):RJ-45
1000 Base-SX/LX: LC
IDU-ODU connectors, cable
attenuation allowed
ODU: N-female 50 ohms
IDU: TNC-female 50 ohms
Maximum attenuation: 25 dB at 340 MHz
(E.g. Draka RFA ½” > 500m)
ODU RX level monitor connector
F-female (DC voltage proportional to the input level at antenna port)
Channel
spacing and
radio capacity
QPSK
7/14/28/56 MHz
11/22/45/91 Mbit/s
16QAM
7/14/28/56 MHz
22/45/91/183 Mbit/s
32QAM
7/14/28/56 MHz
28/56/114/229 Mbit/s
128QAM
7/14/28/56 MHz
39/79/160/320 Mbit/s
256QAM
7/14/28/56 MHz
45/90/183/366 Mbit/s
512QAM
-/-/28/56 MHz
-/-/205/412 Mbit/s
Environmental conditions
(ODU for outdoor use, IDU for
temperature-controlled indoor
use or outdoor cabinet with
similar conditions)
Full specifications: ODU: -33…+50 ˚C, IDU: -5…+50 ˚C
Operation guaranteed: ODU: -40…+55 ˚C, IDU: -10…+55 ˚C
Transportation: ODU, IDU: -40…+70 ˚C
Relative humidity: ODU: 100 %
IDU:

90 % (no condensing allowed)
Power supply
-48 VDC (-40,5… -57 VDC),
Fuse/over current protection > 10A (6A for max 3 x ODU)
Power consumption (1+0)
ODU: 30 W (6-11 GHz), 23 W (13-52 GHz)
IDU:

45 W + 10W/modem + 8W/GbE-card
Total < 210 W (fully equipped, feeding four 6 GHz ODUs)
Mechanical data
ODU: 237(l)x237(w)x101(h); ~3-3,5 kg
IDU: 19” 1U (483x44x240mm); ~3-4 kg (including plug-in units)
LCT (local element
management)
LCT port: RJ45 10/100Base-T using a web browser
Management port
NMS/NE ports: RJ-45 10/100 Base-T
Service Channels (SC)
RS-232C 9600 bit/s 2 ch., V.11 64/192 kbit/s 2ch; D-44 female (See App. F)
External relay output/input
(AUX/ALM)
D-44 female (See Appendix F)
Others
USB-port for a memory stick (USB v.2.0)
Table 4. NEC iPasolink 400 main technical data