PDH & SDH

The telephone network has always been made ​​to reduce the number of wires, conveying on a single transmission medium many users as possible. 
Analog telephone systems are worked by manipulating the signals using frequency division multiplexing FDM . 
With the invention of Pulse Code Modulation (PCM ), ITT took place in Paris in 1939 by Alec Reeves, began the era of digital transmission for telephone signals not telegraph. 
Furthermore in the 50th years was perceived the possibility of obtaining a new method of multiplexing, with time division techniques, TDM, instead of frequency. 
While in the FDM each user has an exclusive possession of a certain band, in the TDM each user in turn periodically obtains the entire bandwidth for a small time quantum. 
PDH 
A Holmdel (New Jersey) was born early sixties the U.S. standard of 24 phonic signals converted first into digital PCM techniques and then multiplexed together with the control bits of the weft so as to form a single signal tributary to 1544 Kb / s called DS-1. 
A few years later the technology made ​​it possible to put together more DS-1 into a single stream of higher hierarchical level. Since all the switching was analog transmission systems used, each on their own, a quartz clock (to convert analog voice into a digital stream that then riconvertiva arrival in analog) was developed a method called "PDH (Plesiochoronous Digital Hierarchy)". 
At the end of the sixties Europeans devised a similar standard, with 30 telephone channels plus a channel for controlling the weft and one for signaling, for a total of 2048 Kb / s. This format is commonly called E1. 
When digital transmission began to emerge with a technology acceptable CCITT was unable to reach an agreement on an international standard. The differences are not just about speed, but concern the length of weft and other interesting issues, it would be complex to explain. 
The table shows the transmission bit rate at different hierarchical levels in a developed tirthy years until the nineties in various areas of high intensity of telephone traffic. 
The European hierarchy is as follows: 
- Four E1 2048 Kb / s form an E2 to 8 Mb / s 
- Four E2 from 8Mb / s forming an E3 from 34 Mb / s 
- Four E3 from 34 form an E4 from 140MB / s 
The Telettra realized and installed on a cable Mux E5 (not standardized) from 565 Mb / s format by four E4.

The only common agreement at all over the globe was the choice of the sampling frequency, 8Khz, the^double-2 of the maximum frequency of the speech channel, which was all over the world wide 4KHz. 
Each sampled value can not yet be encoded as is susceptible of an infinite number of amplitudes between two extremes predetermined. And 'necessary quantization that divides the interval amplitude in small discrete steps. 
In telephony, has adopted 256 discrete levels of quantization. Each level is represented by a code word of 8 bits, accordingly the speed of figure is determined by the ratio between the number of binary digits coding (8) and sampling interval T (125μS) which assumes the value of 64 Kb / S. 
The output signal from the encoder (codec) is constituted by a succession of impulses that in code represents the analog signal. For this reason it is called pulse code modulation signal or pulse code modulation. 

Instead of having n PCM encoders and merge the result into a single digital signal is sampled the Xn (t) voice signals in a round-robin and the resulting analog stream is passed to the encoder. 
The apparatus with which the formation is effected by n signals into a single output stream, is referred to as multiplexer, multiplex or mux simply, the one with which it is realized Li ¿½ operation inversedemultiplexer, demultiplex or demux. 



The architecture represented in the figure is used only for the first hierarchical level. After that, to increase the number of channels in a flow need to enter the many cascaded multiplexers. 
The amount of information and equipment to be used to locate and extract the single channel  is remarkable. The system was the basis of all PDH transmission systems, it is completely flexible, but is the best you could come up in the sixties. He was also the technical reason that justified the telephone monopoly in almost all the nations of the world. 
SDH 
In the eighties, the U.S. government was convinced that the telephone monopoly was illegal. He denounced the judiciary AT & T and won. 
On January 1, 1984, AT & T was divided into 23 companies and other operators entered. 
At that time, scientific research led the purity of glass used in optical fiber attenuation values ​​of these to be spread with all the energy, the convenience of the new means of transport.

The new company had to connect with various PDH operators in most systems with different optical TDM. 
Was necessary standardization, was built in 1989 and introduced a new method called SONET (Synchoronous Optical Network) which was derived from the 'SDH (Synchoronous Digital Hierarchy),which could: 
- Take advantage now that the U.S. was switching systems in numerical and then were synchronized with each other 
- Take the opportunity not only to unify American standards, but also those in Europe and Japan, in order to simplify the intercontinental connections. 
- Being used for the fiber, for the cable and to the radio. 
- Place a minimum of intelligence MUX in order to facilitate operation and maintenance. 
- Establish networks with equipment from different manufacturers and different operators. 
- Be compatible with existing PDH streams. 
This huge standardization work (not yet fully completed) lasted over ten years. 
The SDH is much more than an update of the previous standard is a revolution of the telephone network. Beginning was coupled with PDH system and then almost completely replaced. (PDH Today the system has a new life, 2 to a maximum of 34 Mb / s, only for the connection of stations BTS of the mobile radio network).

The fundamental apparatuses, the SDH system, are the ADM (Add Drop Multiplexer) for the insertion and removal of the numerical flows and DXT (Digital Cross Connect) for the permutation of the traffic at the level of aggregate flows. 
In the second part of the nineties, in Italy, these systems have been incorporated in large quantities in the backbone fiber from 622 Mb / s to 2.5 Gb / s and radio to 155 Mb / s. 
Are present and widespread in the metropolitan area of collection SDH rings that allow you to aggregate traffic in access and channel it towards the junction area.

As to the television signal we have two types of networks. Contribution networks gates opening when the signals from the production centers to the assembly of schedules (playout) and distribution networks carry signals when the playout of broadcast transmission sites to spread to you. 
For these networks, RAI still in different areas uses radio frequency modulation for several years and is starting the installation of radio links with SDH 128 QAM modulations. 
Instead, the first national network of distribution of digital television signals was made ​​by Mediaset and not use either PDH or SDH systems. 

The analog signal converted to digital and compressed to 45 Mb / s used special Coder TV, Modem 64 QAM and 10-GHz radio links, specially designed by Telettra Alcatel Vimercate. 
The transmission speed of these modems, is 90 Mb / s and are able to transfer two coded TV signals in high definition. 
TV signals the arrival in the transmission sites are decompressed and converted back to analog to be transmitted by the fifth round in UHF band. 
Today, in the new systems distribution  both analog (PAL) and digital ( DVB MPEG-2 ) using cable, satellite or microwave links PDH 34 Mb / s SDH EA to 155 Mb / s to transfer to four signals TV simultaneously.

Notes 
1) Plesio, from the greek, meaning "almost". At each speed tributary is allowed an amount of variation, normally of ± 50 ppm (parts per million). 
The multiplexer reads every tax at a rate higher clock allowed and, when there are more bits in the buffer (buffer) in entry (because they're coming in a bit slower clock), it adds a bit to "justify" the signal at the highest speed. 
The Mux has a mechanism to indicate to the demux the fact that has made ​​a justification, so that this last one knows what is the bit to be deleted. 
2) For a sampling frequency lower than twice, the information would be lost at a sampling rate higher than twice, no extra information would be added (on the Shannon sampling theorem)

3) For a variety of reasons, both technical and practical, the shutdown of analog TV can not happen before 2010-2014.

Inside a BTS (video)

CONFIGURATION & INSTALLATION OF A BASE TRANSCEIVER STATION (BTS)

Base Transceiver Station otherwise regarded as Cell is the smallest unit of the Base Station System structure. It’s the area of radio coverage of a BTS. The elements of the BTS are: Mast/Tower, Sectorial antennas, PDH & SDH Microwave, Waveguide cables, Rectifier, Generator, Radio Base Station, Duplexers, Data Distribution Frame rack, Transceiver Unit (TRU), Trunking, TX cabinet & Shelter.

COMPONENTS OF THE BASE TRANSCEIVER STATION

Shelter: This is the housing in which all installations, hardware configuration & termination is done. It usually is 10*10 ft kiosks with provision for two air-condition unit & a feeder window.
-Finally we are going to connect the ESB port on the DXU. The connection goes thus:
1800RBS
Extension
900RBS ESB1 ESB2
1800RBS
Master
-Frequency channel assignment
-Base Station Identity Code (BSIC) configuration.
We have little or nothing to do after our configuration but to commission the site launching the site on our own local network as the case may be.

Mast/Tower: The importance of the tower on the BTS is to have a clear Line of Sight for the PDH/SDH radio & give room for easy radiation of radio signals by the sectorial antenna. The height of the tower is dependent on the topography of the land in focus but the standard recommended height is between 35-40m approximately.

Sectorial Antenna: It’s a broadband antenna capable of multiplexing dual frequency bands for transmission. This antenna radiates at an angle of 120°. For a total coverage, three sectorial antennas are used on a tower to cover 360 ° circumference. It also has a radiation distance of about 35km if concentrating on capacity building for urban areas & 121km when emphasizing on coverage. A clear edge it has over omni directional antenna is that it eliminates the issue of drop calls while roaming.

PDH/SDH Microwave: Plesio synchronous Digital Hierarchy (PDH) & Synchronous Digital Hierarchy (SDH) are microwaves commonly used on the Base Station System. Point to Point (p2p) & Point to Multipoint transmission e.g. Root/Hub station to other BTS sites is facilitated by these radios via line of sight. The PDH microwave has a capacity of 16E1 making it the mostly used for BTS transmission since it gives room for upgrade and it is very efficient in terms of radio transmission to the BSC on the Abis interface. SDH on the other hand has a capacity of 75 E1.Its used basically on the Hub stations for transmission to the BSC on the Ater interface i.e. if you have the BSC & Transcoder Controller (TRC) on a single node . It has a transmission length of about 50km.

Waveguides: As a result of skin effect, waveguides were invented to eliminate or minimize loss of electro-magnetic signals passing through cables in the course of transmission. This black armored like cables have connectors at their tips to fit into the duplexers via feeder window on the shelter. They come in various sizes and have several connecting tips e.g. BNC. Some still refers to it as a jumper cable.

Radio Base Station (RBS): Radio Base Stations (RBS) handles the modulation of speech signals. The Transceiver Unit does basically base band speech processing, abis interface signaling processing, RF signal amplification, modulation & demodulation. Frequency assignment is done on the TRU and the transceiver units are multiplexed in the combiner unit i.e. Combiner & Distribution Unit (CDU). The combiner unit does the filtering of signals from 33.8kbps to 16kbps before its being sent to the PDH from Abis interface. Since the GSM system uses the TDMA technology, several speech signals can be conveyed on frequency. Each physical channel has 8 time slot under this technology. Every logic channel can connect via the slots. Ericsson has several versions but prominent are the RBS 2200 and RBS 2100 versions. RBS 2216 version has six TRU slots for both GSM 900 & 1800 frequencies. It has dummy slots for upgrade purpose The RBS provides interface to mobile station on the air interface also it interfaces the BSC on the Abis interface on the Distribution Switch Unit (DXU).

Rectifier: The RBS works on a 48V d.c. Alternating to direct current conversion is maintained by the rectifier and its output fed into the site voltage regulator. Four 12V d.c batteries are used as backup on the rectifier. The RBS takes it power directly from the rectifier.

Transmission Rack: Otherwise known as TX cabinet, it holds the PDH/SDH radio & contains the connectors on which the alarm, TX/RX installations are done.

Truncking: The trunk consists of a ladder and a bus like rail on which all installation cables/ waveguides run.

Duplexers: The duplexer does de-multiplexing function between the sectorial antennas and the RBS. The sectorial antenna has a dual frequency input. Waveguides connects the input of these frequencies then de-multiplexes. The duplexers have two input and four outputs. Each output connects to each 1800 TRU card on the RBS. A pair of the output on the duplexer for 900 connects to a TRU card.

Data Distribution Frame: The Data Distribution Frame (DDF) or krone box acts as the interface between the Distribution Switch Unit (DXU) and the radio. Its just a connector where all E1 connections & DXU connection is terminated. The PDH radio is hold or supported on the rack.

Having looked at some of the major constituents of the BTS, we can go ahead to examine the step by step way of installing the RBS. We are going to use the Ericsson RBS as a model for our study.

-Firstly, the Ericsson RBS comes with a base which holds it firm & prevents it from any form of corrosion from the surface of the shelter. In placing the base of the RBS care should be taken because there has to be an edge alignment between the RBS and the base. This can be achieved using a plum. The screw at the top of the RBS can then be turned to hold the RBS firmly to its base.

-The next thing is to determine the length of the cables from the power point of the RBS to the rectifier. Note that the power point for the RBS has three points each having provision for live and neutral. It is advisable that the power connection is done last but it is very good to do all measurement before doing the actual cable laying.

-The alarm cable should be plugged into the alarm port on the RBS meant for the 900 TRUs. The other end of the cable should be taken to the DDF rack.

-On the DXU of the 900 RBS, plug the DXU cable into port A & port B of the card. Ports C & D should be left open. This action should be done on both the 900 & 1800 RBS. The other end of the cable is also taken to the DDF rack.

-Fix TRU cards into the slots noting that the number of cards fixed is a factor of the cell configuration. For example, a typical BTS sited in an urban area will use a configuration of 2/2/2 to 6/6/6 signifying that much emphasis is made on capacity building at the expense of coverage. The 2/2/2 to 6/6/6 configuration tells that we will use a total of 3 TRU cards for 900 RBS and 9 TRU cards for 1800 RBS. An understanding of the configuration helps to determine how many TRU cards we are to use on a cell and even provision dummy slots for upgrade purpose.

-Connect your waveguide or jumpers to the input of the duplexer from the feeder window and tighten very well.

-In connecting to the input of the duplexer we should note that the dual input for a duplexer is coming from a single sectorial antenna so that tells us that since we have three sectorial antennas, we will be having three duplexers each for a sectorial antenna. The input of the duplexer has a provision for both GSM 900 & 1800 frequencies separately and this is indicated on the duplexers. For the output port, we’ll see that two ports are provisioned for GSM 900 & two for GSM 1800. Since we are using the 2/2/2 to 6/6/6 configuration as a model for our installation.

-Connect the dual output of the GSM 900 band from the sectorial with your waveguide to a single TRU card on the RBS and repeat the same for the other two duplexers meant for the other sectorial antennas.

-Also, connect the outputs of the GSM 1800 band from the duplexers to the 1800 TRU cards but in doing this we should note that each output from the duplexers goes to a duplexer. We will note that in doing this installation this way, achieving our configuration is not feasible since Ericsson’s RBS 2216 has six slots for TRU cards and we have to use 9 cards for our 2/2/2 to 6/6/6 configuration. Another RBS needs to be deployed known as an extension to augment the other 3 TRU cards needed and give room for upgrade during capacity building but we need to cascade the bus of the extra RBS in other to achieve our configuration.

-Run the cables from the DXU to the krone connector on the rack and the connection should be done based on the number of E1 we are actually using on the site. A CAT 5 cable contains 4 twisted pair cables. Let’s assume we are using two E1 on this site; that means at the other terminal of the DXU cable going to the rack, we are going to cut off two pairs of the twisted cable and use just two pairs. Note that two pairs of the twisted cable make an E1. The crimping of an E1 on the RJ 45 connector is pin 1,2,4,5 with the twisted cables.

ESB1 ESB2

ESB1 ESB2

The hardware configuration involves the determination of the number of TRU units that will be used on the RBS but the software configuration will be done on the Base Station Controller (BSC). Amongst the configuration that will be done is 

-Frequency channel assignment

-Base Station Identity Code (BSIC) configuration.
We have little or nothing to do after our configuration but to commission the site launching the site on our own local network as the case may be.

Implement a project Radio Network Bridge

Notes and Hints for managing a network project in a Radio Link.

Every project manager knows that the success of a project is related to effective control of many variables exist in a project.
Although each project has its own specificity, can be identified, however, common in all phases of the implementation processes. They may be:

• Planning and design of network
• Construction / implementation
• Acceptance and integration

Depending on the type of project and equipment (mobile or fixed network, equipment or split type Indoor, Wired LAN, Hybrid or all packet) the different stages can be distinguished, but now increasingly complement each other because a remarkable "dynamic" in the development of the network (especially in the world Mobile Radio).
Different skills and elements must be taken into account from the earliest design stages. By way of example:

• Definition of the responsibility matrix (internal and client).
• Sites, network topology and connectivity.
• Pre-requisites of traffic, capacity and protection (PDH, SDH, Eth).
• Swaps and planning expansions / replacements.
• Implementation plan congruent with the development of the network.
• Rated mains floor (RF section, Banda and capacity).
• Nominal plan management network (connectivity and IP network monitoring system).
• Plan network services (PDH, SDH, Eth).
• Integration plan services (PDH, SDH, Eth).
• Plan network synchronization.
• Planning Studies visibility (Path Survey).
• Plan visits and preliminary tests on site (Site Survey).
• Studies, projects and planning and infrastructure sites (towers, media, energy, structured cabling etc ...).
• Engineering documentation of the sites.
• Technical documentation systems, manuals, testing protocols and procedures.
• Staff training and selection of consultants and "partner".
• Quality audits.
• Tests, inspections and acceptances.
• Maintenance.
• ...................

The above list may (or rather certainly) not be exhaustive, but to have an idea of ​​the complexity of the activities to be taken into account in a final design.

The table below some ideas of "common sense" to minimize risks and problems during the implementation of a project to link network Radio.

Quickly organize regular meetings with all representatives of the project (not only technical but also commercial).

The implementation of a network in Ponte Radio is an activity that involves expertise in different sectors and not only (as you think) in the party specifically for Microwaves.
The technical elements to be analyzed and the procedures to be applied will be different depending on the type of network, the case of a new network, to expand, upgrade or replacement of existing systems (swap).
Preventive and periodic planning and control allow then to discuss all facets of the project, identifying well in advance of any critical points and being able to plan in advance any corrective actions.
Often the problems encountered during a project arise from an incorrect or incomplete initial planning stage.

Carefully select the team (technical and administrative) and outside companies involved.

Careful selection of the staff certainly lead to a perspective of cost reduction (projected medium / long term). We often tend to focus on reducing the cost of resources and materials (the most competent staff is more expensive), but with the risk of disastrous effects on the quality and professionalism of the service offered to the customer.
Interventions rework and / or re-planning of a network can have very high costs.
The correct selection of technical infrastructure, design and radio network, as well as the necessary equipment and instrumentation are essential for the smooth achievement of the final goal.

Use a selection method that individuals or companies outside the most qualified and on the basis of actual experience (results, projects, clients) and still have a complete view of the entire implementation process.
In some cases it may agree to identify a single company with real experience of turnkey projects, rather than relying on a lot of small companies. A single company can maximize synergies and avoid duplication of work and activities "box" closed, but may cost more?
Let us remember that there are not many companies that are actually able to provide turnkey services.

Some considerations on the type of products and network act as "filters" to select the contractor. A few examples:

• Due to the proliferation of mobile networks and the apparent simplicity of the radio links so-called "split", is becoming increasingly difficult to find competent companies nell'implementazioni indoor systems with elliptical waveguides and antennas large (from 3 meters up.) is not always a company that has extensive experience in mobile networks only know the indoor systems (both in terms of installation and testing, including the correct equipment and instrumentation).
• The evolution of networks from traditional (PDH / SDH) networks in Eth (IP), has resulted in the need to develop the capacity of technicians testing also to the networks. Especially in the future implementation activities towards 4G networks, knowledge networks Eth is becoming increasingly important and should not be underestimated. And 'well structured team with varied responsibilities, is that Radio IP (not easy to find resources with high skills across the spectrum the necessary skills).

Preparation of a preliminary work plan (RF, Management, Services).

Seek the advice of competent and experienced technical staff in order to prepare suitably all phases of the project. Fundamentals are the clarification of the responsibility matrix not only between supplier and customer, but also internally among the various corporate entities.
In many cases a confused assignment of responsibilities is transformed into an implementation confused, with high costs due to continuous rework design is that of implementation.
Proper preliminary plan allows you to:

• Define system-specific and objective of the project.
• Define the responsibilities and tasks.
• Preliminary design of the network (on the basis of maps, some reports from the major sights in terms of both size and complexity).
• Estimation of a list of materials needed.
• Resource estimate time and cost.

At this point, with a clear idea of ​​the project was able to discuss with the various heads approval (or not) of the budget necessary to its realization.
It should be noted that this phase is often required in very short times, therefore the data collected may not be very accurate, then it may have margins of error also relevant. For this reason the preliminary stages of study must be analyzed with experienced personnel with specific experience.
Also remember that the above preliminary analysis (particularly in SDH networks and packet) mustinclude service planning, connectivity and network integration as they can be closely related to the configuration parameters of the system.
Another particular difficulty is the verification of work phases, as more and more often you should plan activities swap, ie replacement of equipment on an existing network.

Perform activities Acquisition with experienced staff.

The tightening of planning regulations and the difficulty of trading sites require specialized knowledge and specific negotiating skills to dialogue with public officials and civic administrators.
We must therefore make sure that the team there is a real expert to negotiate even complex negotiations, as they often turn out to be the main difficulties of a project radio (radio).
The necessary stages of negotiation and technical approvals of a site can take several months.
The head of acquisitions must at least have a knowledge of the systems to be installed in addition to being in contact with the team of Radio planning, in order to evaluate dynamically each time the location of the sites and find alternative solutions in case of problems in the trading sites.
Diplomacy must of course be one of the main features of this person, because it works with different people, always looking for solutions and resolutions to potential conflicts.

Creating the Plan mains voltage.

A network in Ponte Radio requires a careful and detailed planning RF.
A poorly designed network topology may cause a malfunction on the links (propagation, interfering reflections, obstructions, etc ....) causing degradation of quality also remarkable.
In the latest Radio bridges the only static RF planning is not enough, more and more often systems are implemented with "adaptive modulation". It is essential that the planning is done considering Radio in an efficient way the various modulations and not just nominal. It may be "input" for the configuration of priority services.
Degradation also insulated wiring, can have effects in the relevant sections of the network. Make sure you always have the correct information regarding the situation of the sites, the coordinates (including height), visibility between sites and always take into account assessments of alternative candidates as a site can not always be suitable for installation of infrastructure transmission (tower, pole, satellite dishes, etc. ....).
Preferably run whenever possible investigations and field surveys, also to assess elements are not always shown on maps (vegetation, buildings, new and / or abusive, effective heights of buildings / terraces / roofs, etc. .....).

The network plan must also include the analysis of the systems integration and network management traffic.
Of particular importance is the analysis of the traffic in the case of systems to package, since some limitations on the numbers of cascade connections, delay on signals, bandwidth and capacity, can affect the topology of the network.

Schedule a possible activity measurements on links and on-site (Path Survey / Site Survey), if properly done, allows you to save money as it minimizes the risk of error in network design. A network plan may include:

• RF propagation analysis and calculations for the various connections (RF Plan, with calculations of availability, bandwidth, capacity and data antenna systems).
• Analysis interfering with the feedback of bandwidth and capacity.
• Analysis of network parameters for integration management system (IP address, router, routing, .....)
• Analysis of traffic parameters and configuration of services (Distribution PDH, SDH, network analysis parameters including assessments on QoS, bandwidth and priority network service).
• Piano sync.
• ...........

The study plan network will therefore develop

• Forecast on Materials Installation.
• Additional auxiliary equipment and accessory items
• Infrastructure site (Torre, fastening systems for antennas, network grounding, shelter or other housing for equipment, energy systems, structured cabling system, splitters etc ....).
• Detailed work plan with procedures and timing.
• Risk assessment and subsequent action plan (training for work at height, floor safety etc ....).

Preparation materials, equipment, infrastructure and services

During shipping, transport and receiving materials, you should verify that all necessary materials have been ordered and available.
The prior preparation of project documentation (manuals, installation, site folders etc ...) allows you to have a clear idea of the necessary materials to the various sites.
Are not only the equipment, but also the structure of antenna, cables and transmission lines, equipment multiplexes, switches and routers, interconnection systems and structured cabling, power systems including batteries, rectifiers, batteries and more.

In parallel (even before the materials arrive in the system), you should contact the company responsible for external activities, and make sure they are properly qualified to perform all the tasks required, implementation, design (including technical documentation), logistics, coordination and supervision, installation, testing and acceptance. No exception to the necessary equipment for installation and measuring instruments.
The support of qualified staff to support at least in the early stages of Start Up can be useful, especially on projects utilizing new technologies. Remember that thinking to train the staff only courses, may not be sufficient. The completion of the course, after the formal course, is working on a project led by experts ("On the Job Training").

Coordinators and supervisors.

On many occasions you allocate to the project staff with logistics expertise (also excellent) to manage and coordinate the delivery and preparation of materials.
From a purely theoretical point of view it may also be correct since the standardization of sites increasingly leads to manage the materials only as codes and serial numbers.
But a key element is its having a coordinator who is familiar with the materials and systems to install. Personal experience leads me to consider that large errors preparation materials are made just from a lack of knowledge of the materials is in the order in which the sorting site.
A coordinator with knowledge of materials and systems is therefore vital.
Increasingly, it is required that the coordinator, the following is part of "forecast" and preorders of the materials that the process of distribution and installation in the field.
If necessary affincargli an experienced radio especially in the early stages.

Installation and testing of the systems.

Although seemingly the most products "Split" are similar, each vendor has specific details and HW (apparti and materials) and SW (specifications and management system locally or remotely).
Often today's microwave products have design features aimed at optimizing the integration HW between various systems (with the aid of specific accessories) in order to allow for the integration of the special infrastructure site (frames, "cabinet", cabinets etc. ....).

The knowledge of the solutions proposed by the suppliers, allow to install the equipment in multiple installation solutions, precisely in order to optimize the integration site and consequently also the costs.
The installation may include not only the radio system, but also the infrastructure, the energy system, the distribution system as well as other auxiliary apparatuses.

After installation, the system must be configured and suitably tested and proven.
Tests and testing is often performed by documents (test protocols), agreed with the customer, where they will record all the connection parameters, tests and measurements.
Tests and inspections of radio systems include local checks, but also checks the link. The use of two technicians is critical to test the connection (typically a technician Junior and one Senior).

The testing includes checks on guards, and test on the "performance" of the system at both the one-way (a few hours) on the network (end to end) that typically may be required for 24 hours to be made by the remote management system or specific instrumentation.

Do not underestimate the alignment antennas, involving both mechanical installation personnel specifically technical staff (may not be part of the same team). This phase can last a few hours and if performed by a single team to provide appropriate travel time between sites (typically at least 2 trips).

Final acceptance

When you finish testing systems and, where appropriate project documentation (as-build), the system can be put into service and runs what is called "Commissioning" and Network Integration.
The commissioning is systematically initiating the various systems and formalizing the customer to the transfer of responsibility for active service.
Can be performed in collaboration with the customer any procedures put into service in connection with the responsibilities defined in the contractual matrix.
Unless it has been commissioned into service for one way, typically begins with the most important links to go to the sites terminals, rings and terminal connections.
Procedures may differ according to the type of service. 
Typically in packet networks the final configuration of services is made starting from the site of network management, because configurations involving multiple terminals (in addition to being more complex than traditional networks).

In these cases, specific operating procedures must be defined in order to minimize downtime and risk of incorrect configurations that require costly then in the field.

For commissioning procedures are followed specially created called "ATP" (Acceptance Test Protocol). These procedures can be created from standard protocols (or by hand) and "personalized" in relation to the network topology and contractual specifications.

Procedures maximum are typically defined also in the contracting stage for the definition of the responsibility matrix and calculation of the costs / time. They are then magazines in detail during the phases of implementation.
Any case, the project manager will agree on the steps with the customer and present at the end of the work a certificate to record the final acceptance.
This certificate formalizing the handover to the customer in both materials, designs and services.
Of course the same is commenced operations related to warranties, support, repairs and maintenance.

Implement a program of routine maintenance.

A network in Ponte Radio properly designed and implemented does not require much maintenance, if it is installed a remote management system.
We would therefore propose to study and undertake a program of periodic maintenance are essentially two main elements.

• Measures and periodic reports from the remote management system.
• On-site inspections (inspections focused mainly installation, functional and systems not monitored).

Also remember to perform regular maintenance of the equipment in accordance with manufacturer specifications. Especially for lifting equipment (regular security checks) and calibration instrumentation.

Prepared to handle constant change of the network topology and configuration systems.

Especially in Furniture networks, the network in Ponte Radio will necessarily be "dynamic" in the sense that you can easily expect sudden changes in sites, links, implementation priorities, configuration updates, etc. ....
If you are not careful monitoring of network evolution and status of activities, you could easily lose track of changes and updates, then threatening to assess incorrectly possible future activities.

The changes on the network should be carefully considered as they often have a significant cost, often provide a schedule of new materials, a new study network (radio, operation and services), removal and replacement of systems, but especially if they are on sites service nocturnal activity.

To bear in mind that climatic conditions have an influence on work planning, in regions with very low temperatures, you can not always do the outdoor activities, resulting in extension of implementation time.
Many of the activities are outdoors and working conditions which may present some risks, so the attention to risk is fundamental (of course identified and followed by the specifc responsible for safety, according to the specifc practicable rules in different countries).

Conclusions

A clear understanding of the implementation phases of a transmission network for telecommunications, including radio links are essential for the success of the project, whether it is a new network that an extension of an existing network.
A key element is the actual competence of the team, since it must include all the necessary skills, which may not only those on Microwave.

Set up an efficient system of "tracking" of activities, initiate periodic checks on the project with specific indicators, and do not underestimate the processing capabilities of the technical documentation required for the project. Often work on documents issued by central agencies that despite their validity, still need to be adapted to the project.

_____________________________________________________________________

I hope the above tips and notes may be useful.
The article was written based on my experience in supporting the implementation of networks in Ponte Radio as well as some ideas identified in Network

Thanks to my friend and big Telecom Engineer Gaetano Elifani for documents