The Design and Implementation of the BOXER Network Compiled by Aztech
--------------------------------------------------
(Culled from 'British Telecommunications Engineering', Vol 13, Oct 1994)
From what I can determine from this article and the accompanying schematics
and documents,this looks set to mirror AUTOVON in the UK and Europe.
However,whereas AUTOVON can be accessed via the PSTN with a simple extended
DTMF dialset,this looks like it can only be accessed by direct dialling-in
or by radio patching.Also,this Network looks likely to be carrying a high
data ratio,due to the amount of cash being lavished on the Intra-Node links.
Eavesdropping is out of the question,as the system will no doubt be
implementing the TEMPEST security measure.For more info on TEMPEST and its
implications,read the end of this file.
***** ***** ***** ***** ***** ***** ***** *****
The BOXER Network,one of the largest private networks in the UK,provides
nationwide connectivity to RAF and other military and government users.
This article describes various aspects of the network,which has been designed
and implemented by Syntegra,BT's systems integration buisness against
exacting Ministry of Defense requirements.
INTRODUCTION
------------
The BOXER Network has been designed and implemented by a dedicated project
team within Syntegra,BT's systems integration buisness,against a Ministry
of Defense(MoD) contract placed in 1987,with a scheduled completion and
final handover date to the RAF of June 1996.
The BOXER Network provides full nationwide connectivity to RAF and
other military and government users as part of one of the largest private
networks in the UK.The Network forms the transmission element of the RAF
fixed telecommunications sytem(RAFFTS).As a military network the system
has been designed to meet the specified requirements of security and
survivability.
BOXER consists of over 200 individual sites,the majority of which
are further broken down into subsites.The basic topology is shown in Figure 1.
As a standalone MoD network,one of the primary design aims upon BT was
diversity from existing BT sites wherever possible.BOXER uses optical-fibre
and microwave radio systems to provide the bearer network,and operates at
hierarchical data rates up to 140 Mbit/s.A general outline of the Network is
shown in Figure 2.The Network consists of over 4.5M channel kilometres of
64 kbit/s digital paths.
One of the first decisions made was how the project should be
organised,given the size,complexity and geographical spread of the network.It
was concluded that the use of a phased approach,with each phase consisting
of six month periods,provided the most manageable solution.Using this as an
objective,the project was broken down into specific design/implementation
elements,the functions and operations of each being as follows.
NETWORK DESIGN:
---------------
The project team recruited Network radio and cable planners from what is now
BT Worldwide Networks to carry out the the detailed design work.
The design of the microwave network used the experience built up by BT
research at Martlesham Heath for the main BT network,and relied on the proven
computer aided design packages developed there.Among the software packages
used heavily is the Peacemaker path profiling and interference study suite
of programs.Having completed desktop studies using these systems,detailed
route and site surveys are undertaken in order to confirm the equipment
configurations to be supplied,tower availabilty and antenna mounting access
at the required heights.
Cable planning operates in two major areas,on site and access.The
on-site cable planning identifies the routes required between the microwave
radio access site and that of the end traffic user(see figure 1).
FIGURE ONE : BOXER TOPOLOGY
---------------------------
RADIO TESTABLE SECTION
SUB SITE *{======}**{===============}*
* ** *
+---BOXER TPB---+ * ** +---+ * +--------------+
| +--+ +--+ | * ****| | * | +--+ +--+ |
| | |*| |********* ****| | *********| |*| | |
| +--+ +--+ | +---------------------+ | +--+ +--+ |
| * | | HILL TOP | +-------- * ---+
+----*----------+ *
* RADIO REPEATER *
* *
* CROSS-SITE TIE TESTABLE SECTION *
* *
+----*----------+ +-------------*-----+
| * | | * |
| +---+ | | +---+ |
| | | | | | | |
| +---+ | | +---+ |
| SWITCH | | +---+ |
| +---+ | | | | |
| | | | | +---+ |
| +---+ | | * |
+----*----------+ +-------------*-----+
* *
+---+ FIBRE REPEATER +---+
| |******************><***********><*********************| |
+---+ +---+
OPTICAL FIBRE TESTABLE SECTION
RAF BASE STATION RAF BASE STATION
TPB:TRANSPORTABLE PREFABRICATED BUILDING
*** INDICATES PHYSICAL LINK
=== INDICATES RADIO/MICROWAVE LINK
Access Planning concerns those routes where fibre provides the
transmission medium into the site via dedicated duct installed in public
highways in a matter identical to BT and other utilities.As such,the
requirements of the New Road and Street Works Act and its predecessor
The Public Utilities Street Works Act(PUSWA)apply and need to be considered
and implemented in addition to project specific requirements.
The culmination of the above planning actitivities is the
identification of all elements required to be provided on a site in terms of
civil works,etc.in order for the project to be implemented.This information
is embodied in a site-specific civil-works requirement document,which is
issued to the MoD or the site owners by the project team with sufficient
lead-time to ensure that works are completed by the planned site
implementation date.
The final planning activity concerns traffic and network sizing: The
overall network traffic requirements and connectivity are the responsibility
of the RAFFTS planning team;the physical implementation in terms of capacity
and multiplexing lies with the BOXER project team.The results of this planning
effort are specific multiplex and equipment plans for each site in the
network;these are used to define the equipment fit for each location
(see later).
EQUIPMENT:
----------
The BOXER Network utilises over 30 major items of equipment ranging from
power supplies including stand-by generators and rectifiers,transmission
equipment(Multiplexers through to Microwave Radio Systems) and equipment
housing.Of these the most important is the Transportable Prefabricated
Building(TPB).This is the cornerstone of the project,as it provides security
and survivability protection for the transmission and ancilliary items of
equipment.The TPB in its final configuration provides enviromentally
controlled power and equipment mounting areas seperated by a fire wall,each
with its own means of external access.External Protection for the TPB
is provided by insulated moulded weatherproof GRP panels,which are designed
to blend with the location by means of various finishes:for example,brick or
plain coloured as standard,or others to meet special requirements.
The overall dimensions of the TPB(7m x 3m x 3m)allow for
transportation by road,and the design is provided with suitable lifting points
not only for craning on and off the low loaders for road delivery,but also
for helicopter delivery to remote locations.
The procurement of all items of equipment is based on competitive
tendering exercises managed by the BT Group Procurement Services personnel
allocated to the project.Each item of equipment required is based on standard
commercially available items wherever possible to minimise specific develop-
-ment programmes and products.These are then evaluated against project
specific facility requirements contained in BOXER specifications.These
documents,allied to specifications defining the BOXER project requirements
in both the commercial and quality assurance areas,form the basis for the
tender adjudication exercises.
The procurement exercises operate under a strictly formalised
methodology based on acheiving an overall value-for-money solution covering
whole-life costs.These exercises resulted in over 500 individual tender
responses to the various requests,and,after adjudication and acceptance by the
MoD,resulted in contracts worldwide with various major telecommunication
suppliers.
IMPLEMENTATION:
---------------
The size of the Network and the time scales required neccesitated a structured
programme of implementation.This programme consists of three distinct elements:
ELEMENT 1(RELEASE POINT 1)
--------------------------
This element concerns the procurement and delivery of the individual equipment
items from the manafacturers.Each equipment type used within the project is
subjected to a specific type-approval exercise to confirm compliance with
the network performance requirements.Based on these tests,a set of release
criteria are then agreed with the companies;these criteria are used by the
projects quality assurance (QA) personnel as a basis for acceptance of
each batch of equipment.Based on their performance in this area,and to
maximise effective use of the projects QA resource,companies are encouraged
to achieve 'delegated release status' with batches of equipment being
released under certificates of conformance issued by their own internal
QA organisation.
Delivery of the procured items directed to one or two specific
areas:either the centralised installation facility (Element 2 below)
or direct to site in case of items such as antennas and associated mounting
steelwork.
ELEMENT 2(RELEASE POINT 2)
--------------------------
This element concerns the site specific configuring of the TPBs.In order to
achieve this,a centralised installation facility was developed and operated
by Fujitsu Fulcrum Communications Ltd. under a BT contract.This facility is
required for two reasons:
*The range of items to be installed in the TPB with the associated fittings
and fixings precludes this as an on-site operation.
*The installation rate required(an average of 44 TPBs per year)demanded
significant manpower with limited scope for efficient utilisation given the
wide geographic spread of sites.
The manufacturing cycle through the centralised installation facility follows
a standard sequence,which is now described.
The configuration in terms of equipment fit is identified as part
of the network design and planning functions of the main BOXER team.
This information is then transmitted to Fujitsu Fulcrum.Fujitsu Fulcrum is
responsible for designing and fitting out the TPB under the overall
management control and supervision of the project.
Initial fitting out includes the provision of overhead ironwork and trunking
to support the TEP-I(E),CEPT slimline or other equipment housing requirements.
AC electrical power wiring is then installed to complete the basic fitting of
the building.The building is now ready for the equipment to be installed.
Radios utilising CEPT slimline practise and the TEP-I(E) racks containing
the multiplexes and optical line terminating equipment are fixed to the
overhead ironwork.
The power equipment consists of two primary elements,both based on
standard BT products.The first,installed in the power room of the TPB,is the
stand-by generator(PS 4006 equivalent) and its associated ventilation/exhaust
system,and the second is the rectifier and stand-by battery system EP2008B
installed in the equipment room.Once the physical installation of the
equipment is completed,the remaining power and transmission cabling can be
undertaken.When this is completed,the configuration and connectivity of the
equipment elements via digital distribution frame(DDF) cabling is matched
to the defined traffic connectivity requirements for the site the TPB is
allocated to.
The final element of the Fujitsu Fulcrum manafacturing cycle is
testing(see later).The design of the Fujitsu Fulcrum facility allows for the
benifits of a full factory manafacturing cycle to be implemented.This cycle
takes 12 weeks to complete for each TPB,and at the production rate required
for the project,12 TPBs will be in manafacture at any one time.
This structured process allows for maximum throughput in a controlled
manner,and provides for efficient utilisation of the available manpower
resources and skills.
ELEMENT 3(RELEASE POINT 3)
--------------------------
The final implementation element is installation on site and associated
testing/commissioning.BOXER sites are located throughout the UK mainland.
Although Road access is acheivable at all sites,in several cases four-wheel
drive or special purpose vehicles have to be used.In these cases,delivery
of the TPB on its standard road low-loader transport can prove impossible:
A helicopter or other speciaist delivery system is then neccesary.
A fully equipped TPB weighs between 9 and 10 tons,which is just within the
maximum load of an RAF Chinook depending on how far the building has to be
carried from the access to the site.As stated earlier,the TPB is designed
with appropriate lifting points to facilitate this delivery method,which has
already been successfully utilised,and is scheduled for a number of other
site deliveries before the project is completed.
Each site must be equipped with appropriate mounting facilities for
the TPBs.These foundations and associatied other civil works,for example,
ducts etc..have to be completed before deliveries are commenced.The
off-loading of the TPB,as is the mounting of antennas on microwave towers,
is managed by BT Worldwide Networks via a service level agreement.Their
responsibilities cover the off loading and safe bolting down of the TPBs,and
the installation,panning and testing of the antenna systems.
Once a TPB is bolted down,the responsibility for installation reverts back
to project personnel.The building is unpacked and the task of recommissioning
starts.This occupies amny functions:connection of the TPB to its primary 240v
AC power supply,the connection of the stand-by generator to its fuel supply,
fitting of weather-proof cowls over the enviromental ventilation grills,
and re-installation of the transmission equipment modules/cards into their
rack positions.These items are demounted and packed for transportation
purposes by Fujitsu-Fulcrum before dispatch as a general policy,although
tests proved that transportation of a fully equipped building is a viable
option for most of the UK sites.Once the physical reinstatement of the TPB
is complete,power can be connected to the equipment to allow testing to take
place.The objective is for the primary power to be connected to the TPB
such that the enviromental control systems (heaters/fans) are operational
on the day of delivery;a stable enviroment for the implementation personnel
will therefore exist during testing and commissioning.
Once all the testing is completed,the building is cleaned and the internal
cabling connections on the DDF are returned to the traffic design requirements
before handover to the customer.Figure 3 shows a typical TPB installation.
(Figure Three shows a photo of a BOXER node in action.The Building containing
the communications equipment is seperate from the tower holding the
Microwave Transmitter/Receiver.Judging by the cable thickness and the overall
dimensions of the dish,it looks like a VERY powerful setup.-=[AH]=-)
PERFORMANCE
-----------
The performance of the network is assessed in two ways,firstly in terms of
individual equipment elements and secondly in terms of the network itself.
EQUIPMENT TESTING
-----------------
The testing strategy adopted in the project follows similar lines to that for
implementation:the concept of reducing structured testing through the three
stages identified as Release Points 1,2 and 3 allows for minimum staffing
levels and time on site.
RELEASE POINT ONE
-----------------
This testing covers the factory release of the individual items from the
manafacturers.The tests are derived from those used for design acceptance,
and are used by the project QA personnel to assess each company's performance
against the company's quality plans.Formal acceptance of batches of
equipment requires either on-site visits or acceptance of certificates
of conformity issued by the individual company's QA authorities.For the
microwave radio systems,these tests have to be carried out on equipment
configured as 'hops' and incorporate both equipment and hop testing.This is
made possible since equipment is ordered on this basis,and not on individual
terminal ends.
Under the contracts the manafacturers must hold full records of all
the test results,as refernce sources for both BT and the MoD quality
assurance departments,and are used as reference data for the regular audits
identified in the agreed quality plans.
RELEASE POINT 2
---------------
Two stages of testing take place at the centralised installation facility:
goods inwards and goods outwards or final release.
* Goods Inwards Testing
Owing to the complexity and numbers of different items involved within the
project,the need for initial testing upon delivery to the CIF to check for
damage in transit and basic functionality is essential.On many of the items,
for example,multiplexes and line terminating equipment,this utilises standard
test-rigs;however,for the larger more complex items,particularly the radios,
full assembly becomes a prequisite of testing.Because of this,Fujitsu Fulcrum
modified the goods-inward testing strategy for the radios to incorporate hop
testing as a more effective method of proving performance.Certain items of
equipment can be functionally tested only after installation in the TPB,
particularly the COMPAC stand-by generator.Goods-inwards testing of this and
similar items is therefore limited to signs of visible damage.Having some
degree of certainty that the individual items are functional,installation in
the TPB then takes place.
*Goods Outwards Testing
This testing is undertaken once full installation of the equipment is
completed.As identified earlier in this article,each TPB is configured on a
site-specific basis equating to the traffic levels both through and terminal.
Thus by means of the DDF,equivalent traffic paths can be constructed within
the building to verify performance and interoperability between the equipment
items.Looping at IF on the radios allows for at least partial verification
of those items allied to single terminal testing of parameters such as
output frequency,power and spectrum.With the genertaor installed in the TPB,
along with its associated input and exhaust systems,verification that it
will start and run satisfactorily can now take place.Also the wiring of the
TPB is tested and certified as being in accordance with the IEE wiring
regulations.
Once all this testing is completed,a certificate of conformance is issued
and the TPB is prepared for dispatch to site.As with Release Point 1
testing,all test results are held by Fujitsu Fulcrum to be used as a basis
for ongoing project and QA audits.
For those items of equipment delivered direct to site,for example,
waveguide and antenna systems,optical-fibre cables etc.,the requirements
for Release Point 2 Testing are waived.
RELEASE POINT THREE
-------------------
On-site testing is limited to that necessary to confirm that no damage has
occured in transit for those items delivered from the centralised
installation facility,to verify the performance for those items delivered
direct to site,for example,antenna and feeder systems or installed
optical-fibre cables,and to test overall radio hop/optical fibre sections.
BT Worldwide Networks install and comission the antenna andwaveguide feeder
systems and pan the links.Gas barrier-to-gas-barrier loss and swept-frequency
return losses provide acceptance criteria for this work.
Testing of the equipment within the TPB or end-user cabinets is carried out
by the project implementation managers and engineers against a set of
procedures defined and agreed with the MoD.Hop/fibre section testing is
carried out against targets derived from the network performance
objectives described in the next section,and these results form the basis
for final acceptance by the MoD.
FIGURE FOUR - BOXER HYPOTHETICAL REFERENCE DIGITAL LINK
- - - - - - - - - - - - - - - - - - - - - - - - - - - -
+-----+
*-----| LTE |-------------+
PRIMARY +-----+ |
TRUNK SWITCH +----+----+
| LTE |
+----+----+
|
+----+----+
| 2/8 MUX |
+----+----+
|
+----+----+
| 8/34 MUX|
+----+----+
|
------- +-----+-----+ -------
| |RADIO TERM | |
| +-----+-----+ |
| | |
| +-----+-----+ |
100 km |RADIO RELAY| | 4.5 Ghz
| +-----+-----+ | RADIO
| | |
| +-----+-----+ |
| |RADIO TERM | |
------- +-----+-----+ -------
|
+----+-----+
| 8/34 MUX |
+----+-----+
|
+----+-----+
| 8/34 MUX |
+----+-----+
|
+----+-----+
|34/140 MUX|
+----+-----+
|
------- +----+-----+ -------
| | FOC LTE | |
| +----+-----+ |
| | |
| | |
| | |
75 km | | | FOC
| | |
| | |
| | |
| | |
| +----+-----+ |
| | FOC LTE | |
------- +----+-----+ -------
|
+----+-----+
|34/140 MUX|
+----+-----+
|
+----+-----+
| 8/34 MUX |
+----+-----+
|
+----+-----+
| 8/34 MUX |
+----+-----+
|
------- +-----+-----+ -------
| |RADIO TERM | |
| +-----+-----+ |
| | |
| +-----+-----+ |
75 km |RADIO RELAY| | 15 Ghz
| +-----+-----+ | RADIO
| | |
| +-----+-----+ |
| |RADIO RELAY| |
| +-----+-----+ |
| | |
| +-----+-----+ |
| | RADIO TERM| |
------- +-----+-----+ -------
|
+-----+-----+
| 8/34 MUX |
+-----+-----+
|
+-----+-----+
| 2/8 MUX |
+-----+-----+
|
+-----+-----+
| LTE |
+-----+-----+
|
+-----+ |
*----| LTE |---------------------+
+-----+ FOC:FIBRE-CABLE
LTE:LINE TERMINATING EQUIPMENT
PRIMARY TRUNK SWITCH
NETWORK PERFORMANCE
-------------------
The BOXER network performance is assessed by using the principles defined in
CCITT Recommendation G.821. With the mix of data rates between 2 and 140
Mbit/s,and the configuration of the network,sections of the 'high,medium and
local grade' elements of the hypothetical reference digital link (HRDL)
defined in G.821 need to be considered.By using G.821 as a basis,a specific
BOXER HRDL (See Above) has been derived and agreed with the MoD and their
supporting technical experts.From this,performance targets in terms of
errored seconds and degraded minutes are derived on a per kilometre route
basis.The performance targets for each link within the network can then be
calculated relative to its path length.
The network is considered as a series of testable sections(See Figure
one) and performance is verified on each of these.Since each sections
performance is calculated on a per-kilometre basis,chaining series of sections
together to form logical links allows the overall end-to-end section
objectives to be met.The acceptance of each section by the MoD as they are
completed is based on the results of a final 200 hour stability run
against calculated targets allied to confirmation of testing at Release Points
1 to 3 as defined above.
In terms of the BOXER Network,overall performance lies between the
'high and medium' grade CCITT objectives;however,by planning the network
solely against the 'high grade' criteria,the customer gains benefit in
terms of reliability and performance.
The performance of the network against the objectives is the subject
continuous monitoring throughout the implementation programme by the BOXER
team,and the RAF provides results on the transferred sections.So far,
in annual assessments,BOXER has comfortably exceeded all its targets by a
considerable margin.
(The BOXER project is due for completion in June 1996.)
***** ***** ***** ***** ***** ***** ***** *****
The article then went on for about a page about the Managerial structure
of Syntegra,and how clever they all were,and how it was such a wonderful
idea,bleh,bleh,bleh..You get the picture.
PROJECT TEMPEST,AND ITS PART IN THE BOXER NETWORK:
--------------------------------------------------
More info on Tempest can be obtained from:
Christopher Seline
cjs@cwru.cwru.edu
cjs@cwru.bitnet
TEMPEST(Transient Electromagnetic Pulse Emanation Standard)
is essentially an electronic bugging standard/implementation(?) which
allows anyone with a suitably equipped CRT and Scanning/synchronization
equipment to receive visual data from a nearby computer system,and view it
as if it were on their own terminal.These sets are readily availble if
you know where to look,and furthermore,this form of eavesdropping is -not-
illegal in the UK.This works by pulling in EMR from the target set,and
decoding or emulating the info for human viewing.In the US,it is actually
illegal to try and prevent this,but the UK has still to realise that
it falls outside its current legislation on telecommunications.(TEMPEST
is a Passive device for intercepting un-intentionally transmitted data).
The MoD will no doubt be taking steps to minimise any emanations that could
compromise its security,but until BOXER goes on-line next year,we wont really
know.It -would- be intresting to see exactly what goes round that
particular network...
---=[AZTECH]=---