Telecommunication network management system (TNMS) is one of the most important tools to operate high efficiently a small telecommunication network. In the past years, how to build fast and reasonably TNMS has been being a very important and complex problem to be solved so as to improve the quality of network operation. Due to the vary kinds of new techniques and equipment used widely in the networks, the requirement for ability to analyze and process the spatial information about the network operation has largely and fast increased in TNMS. This paper discusses mainly the key technique to develop the real time and high quality TNMS based on PC ARC/INFO. Thus, this paper introduces a graphic model for the operation management of small telecommunication network, which is based on the computer network clustering construction theory and can be implemented in the environment of PC ARC/INFO. Further, this new theory transforms a complex problem of the operation management of network into a simple problem about the graphic processing in the graphic model. On the other hand, the excellent ability of PC ARC/INFO to analyze and process the spatial information, including the operation of various complex graphic information,is used to implementthisgraphic model.
1.INTRODUCTION
Telecommunication network has very wide meaning, and is usually a
complex system which may be a computer network, telecommunication
network and ISDN network, etc.. A management system of
telecommunication network is really a very important tool for
operating effectively the network, and becomes also a very important
part of today telecommunication networks (Cassel, 1989). While the
complexity of telecommunication networks is increasing,the importance
of management system for the operation of telecommunication network
is also increasing. Obviously, this importance may be the same as that
of common computer operation system for computer operation, and
further, the former may be more important. In general, a
telecommunication network system of high efficiency and performance
must have a network management system of good performance. Otherwise,
it is not possible that this telecommunication network is effectively
operated. Further, because telecommunication network is usually also a
computer communication system of high speed operation, the time
performance of this operation management system is very important for
the real time performance of telecommunication network.
In the management of telecommunication network of the above
discussion, the performance management of network is one of very
important problems to be solved(Ball, 1992). The performance
management includes usually the management of the time measurement,
e.g.the average delay time, information processing speed, e.g. the
information throughput, and the operation status of the network which
relates to provide the various services for users of the network. In
fact, the key task of the performance management of network is to
adjust reasonably the information flow in the network so as to make
the operation status of the network satisfactory and to increase the
efficiency of operation of the network infrastructure as largely as
possible. However, the performance management of network is still a
very complex problem in the current time, and so far is not solved by
any satisfactory method. The major reasons of production of this
situation are that telecommunication network is a very complex
computer system and that to describe the performance and status of the
network by an uniform and global view is very difficult. Thus, it is
very difficult to define a standard for specifing and determining the
performance of telecommunication network. So far, we have really no
any effective method for managing the performance of operation of
telecommunication network (Tjaden, 1991). Besides the above reasons,
the performance managements in the current management techniques of
telecommunication network are only to diagnose the network faults, to
recognize reason of the network faults and to recover them to the
normal operation (Lewis,1993). Thus, this performance management of
network is really the performance management of a passive-response
mode, and can not provide the performance management including the
information flow management in a uniform and global view. Especially,
the ATM(asynchronous transfer mode) network is being widely used in
local or wide area so that the importance of the performance
management of network, including the information flow management, is
increasing. Obviously, the ATM network without the support of this
performance management is certainly low efficiency. Further, the
performance management, including the information flow management, in
future telecommunication networks will become a very important task of
both the performance management of network and the network operation
(Samani, 1993). In general, the above information flow management
includes two main contents as the following:
1)Manage the information flow pattern of total network in order to
make the network operation on the pattern as good as possible;
2)Recognize abnormal information flow pattern, find out the reason to
result in this pattern, and adjust it to a normal pattern.
This paper is divided into six major parts, and discusses a new
method for the real time management of small telecommunication
network. By this method, one uniform and global view can be built and
used to define the operation status of small telecommunication
network. Otherwise, an effective model of the performance management
of network is used to manage this global view of small
telecommunication network. In the second part, a general model for
supporting the real time system for operating small telecommunication
network and how to apply it to describe the operation status of
network are discussed respectively in detail. In the third part, the
PC ARC/INFO implementation of this model and some key techniques
related to it are discussed. In the fourth part, some typical
operation process of the real time management system based on this
model is discussed in order to show the implementation of the above
key technique. In the fifth part, a typical example is discussed for
showing a general method of implementing this real time management
system. In the sixth part, some further works related to this real
time management system are discussed.
2.GRAPHIC MODEL FOR REAL TIME MANAGEMENT
How to apply an uniform view to describe the operation status of
telecommunication network is the first problem to be solved for
building a model for operating the network (Snodgrass, 1988). We note
that, for any telecommunication network, supposing it as N0, its
design and implementation are usually completed in an environment E0
which is described by a ideal and the supposed parameters. Thus, we
define a sequential pair of (N0, E0) as a status of the network N0. In
fact, after the telecommunication network is operated, both N0 (here,
N0 is also considered as a final design and implementation of the
network) and E0 are variable. In general, the faults and changes of
some components in N0 make the performance of N0 change. Further, we
can use a weighted special topology to represent the status of the
network N0. The weight is usually used to describe some physical
parameters, including the information flow, delay time, throughput,
cost and reliability, etc.. Obviously, the changes of N0 can be
represented in the changes of the weighted parameters and the special
network topology. Otherwise, all values of these parameters of N0 can
be divided into the two spaces Ns1 and Ns2. The N0 in Ns1 represents
that the status of N0 is acceptable, i.e., the operation status of N0
does not degrade the primary goal of the performance of design of N0.
on the other band, the N0 in Ns2 represents that the status of N0 is
not acceptable, i.e., the operation status of N0 degrades the primary
goal of the performance of design of N0 . Because the E0 is also
variable, in the same way, the all values of E0 can be also divided
into the two spaces, the Es1 and Es2. Further, the values of E0 in Es1
represents that the status or values of E0 are accepted, i.e., the
operation environment E0 of N0 satisfies the primary goal of design
environment of N0. Otherwise, the values of E0 in Es2 represent that
the status or values of E0 is not accepted, i.e., the operation status
of N0 in E0 degrade the primary goal of the performance of design of
N0. Thus, we can obtain the description of four combination spaces
based on the Ns1, Ns2, Es1 and Es2, which is discussed as the
following:
XS11=(N0 in Ns1, E0 in Es1), XS11=(N0 in Ns1, E0 in Es1)
XS21=(N0 in Ns2, E0 in Es1), XS22=(N0 in Ns2, E0 in Es2)
Obviously, the set XS=(XS11, XS12, XS21, XS22) describes all possible
operation status of telecommunication network, where the XS11
represents the normal operation status of N0, and the XS12, XS21 and
XS22 represent the abnormal operation status of N0. Further, we can
find some important relationships between the above one status and the
other status. For example, the status XS12 may be transformed to the
status XS11 by the adjustment of the performance management of N0. The
status X21 represents that there are some faults in N0 and this status
must be recovered to the normal status by the recovery management of
faults of N0. In the most situations of application, the status XS22
is transformed into the status XS11 by the performance and fault
managements of N0. The four status about the operation management of
telecommunication network can be described as the relation XS22->XS21-
>XS12->XS11 and XS22->XS12->XS21->XS11. Obviously, this relation
describes the decision of operation management of telecommunication
network, i.e., how to transform the worst abnormal status (for
example, XS22) into the normal status. In general, there are the two
paths in this relation, called the upper path and the lower path
respectively, which can be used to implement the transformation
between the XS22 and the XS11. Further, the two paths can be described
as the path (XS22, XS21, XS12, XS11) and the path (XS22, XS12, XS21,
XS11) or can be simply represented as the paths PXS1 and PXS2,
respectively. It is possibly show that the decision PXS1 of operation
management of N0 is more effective than the decision PXS2. For the
simplicity, we show only the existence of the paths PXS1 and PXS2,
here.
Theorem:For any telecommunication network (design) N0, let its
design environment be E0, then there are the two above management
decisions PXS1 and PXS2.
Proof:Since the design and implementation of N0 is based on the
environment E0, the N0 can be represented as N0=f(E0), where f is a
design function of wide meaning and E0 is variable. Further, for any
telecommunication network N0 and the operation status (N0, E0) of N0,
we have that (N0, E0) is in {XS11, XS12, XS21, XS22}. Let XS1={XS11},
XS2={XS12, XS21, XS22}. Because the goal of the performance management
of telecommunication network N0 is to make the (N0, E0) equal to the
XS11 or (N0, E0) be in XS1, the decision M={M1, M2, ..., Mr} of the
operation management of telecommunication network N0 is to make
M*{(N0, E0) in XS2}={(N0, E0) in XS1} while the (N0, E0) is in XS2,
where the operation * represents the action of management decision.
Further, let the (N0,E0)=XS22, we can show that there are the Mi and
Mj in them, so as to make Mi*{(n0, E0)=XS22}={(N0, E0)=XS21} or
Mj*{(N0, E0)=XS22}={(N0, E0)=XS12}. Because {(N0, E0)=XS12} is not
equal to {(N0, E0)=XS11}, {(N0,E0)=XS21} is not equal to {(N0,
E0)=XS11}, and there is Mi and Mj for Mi*{(N0, E0)=XS21}={(N0, E0)=
XS11} or Mj*{(N0, E0)=XS12}={(N0, E0)=XS11}, thus, there are the
management decision PXS1 and PXS2.
The above theorem has clearly described the basic method for
operating telecommunication network. However, how to represent the
status (N0, E0) of the network N0 and how to determine the states
XS11, XS12, XS21, XS22 are two key problems to be solved for
implementing the above management decision. In fact, we can find
that the above decision is really a decision based on the management of
graphics. Thus, the operation management of telecommunication network
N0 is really converted into a series of the management of graphics,
where the graphics describe the various operation status of N0. This
view shows also that we must find out some special graphics relevant
to the various operation states of telecommunication network N0 for
describing these states. Thus, we will introduce a new effective
theory, called the computer network clustering construction theory
(CNCCT), for showing how to construct the various graphics relevant to
the status, e.g., (N0, E0), XS11, XS12, XS21 and XS22.
The CNCCT thinks that, for any given design environment E0 which
includes usually the user requirement and the basic infrastructure of
telecommunication network, etc, we can construct a clustering tree of
the network as the final design of topology of the network, and any
other non-tree topology of the network can be generated from this
clustering tree. Obviously, while the E0 varies, the relevant
clustering tree varies certainly, so that this clustering tree becomes
really an effective tool for describing the variation of the operation
environment of telecommunication network. Further, the operation
management or performance management of telecommunication network is
really the management of various clustering trees (Note, a tree is an
interesting and flexible data structure). Thus, the complex problem of
the operation management of telecommunication network can be converted
into the graphic management of the above special clustering trees. In
general, this graphic management about the clustering tree requires a
lot of operation about PC ARC/INFO, so that the ability of PC ARC/INFO
to analyze the spatial information can be directly used to implement
the real time management of operation of telecommunication network.
For the convenience of the following discussion, we describe
further a telecommunication network N0 as TN0, where TN0 represents a
typical clustering tree about N0. In the same way, the operation
environment of telecommunication network N0 is described as TE0, where
TE0 represents also a clustering tree about E0. In fact, it is
reasonable that the clustering tree is used for describing the
implementation environment of N0, because we can use the interaction
frequency among all users of N0 for constructing a clustering tree
based on the frequency. Obviously, in the early stage of the operation
of telecommunication network, the N0 is suitable for the E0, or
TN0=TE0. However, we can use the same method as the above one of
defining the status of telecommunication network for defining the
status of the clustering tree as TXS1={TXS11} and TXS2={TXS12, TXS21,
TXS22}. Further, we can also use the paths TPXS1 and TPXS2 for
managing the telecommunication network N0. In the above description,
we note that TN0 and TE0 are variable, so that the TN0 and TE0 can be
represented as the following form:
TN0={TN00, TN01, TN02, ...}
TE0={TE00, TE01, TE02, ...}
Where all elements in the TN0 and TE0 are the clustering trees.
Thus, the goal of selection for the operation decisions is to make
{TN0=TE0}={TN00=TE00, TN01=TE01, ...}, and the (TN0, TE0) is in TXS1
and the (TN0, TE0) is not in TXS2.
3.PC ARC/INFO IMPLEMENTATION OF GRAPHIC MODEL
In the above discussion and analysis, the real time management of
operation of telecommunication network is really transformed to the
management of some special clustering trees. Thus, the complex problem
of the real time management of telecommunication network is also
transformed to the simpler problem of the graphic management in the
graphic model, so that an uniform and global view is used to describe
the problem of the operation management of telecommunication network
with the help of a method of graphic operation. In order to implement
the graphic model of the operation management of network in the
environment of GIS(Bernhardsen, 1992), there are three problems to be
solved, which are discussed as the following:
1)How to build a correspondent relationship between the abstract
clustering tree and the infrastructure of small telecommunication
network, for example, the relationship between the TN0 and the
practical small telecommunication network;
2)How to manage the clustering tree with the help of the ability of
PC ARC/INFO to analyze and process the spatial information;
3)How to apply the model based on the clustering tree for operating
the small telecommunication network.
The answer to the first problem is very simple. As the former
discussion, for any telecommunication network, a relevant clustering
tree can be constructed and be finally described on a graphic coverage
about geographic information. With the database in PC ARC/INFO, the
basic relationships between the nodes and arcs of the clustering tree
and the infrastructure of small telecommunication network are easily
built, so that the relationship between the TN0 and its practical
small telecommunication network is also built. On the other hand, for
the fault diagnosis and the performance optimization of small
telecommunication network, this relationship is very important. For
example, after the current clustering tree is compared with its
standard clustering tree by a special algorithm, the abnormal
situation of the current clustering tree, including the nodes and
arcs, can be determined, so that the information about this situation
can be used to determine the position of fault elements in small
telecommunication network or to optimize the performance of the
clustering tree as well as the small telecommunication network with
the method of the performance optimization.
However, the second problem is very complex, because it relates to
the management of current clustering tree of small telecommunication
network. This management includes two main contents, which are
discussed as the following:
1)Determine the performance of current clustering tree or the abnormal
situation in this clustering tree;
2)Recover the abnormal clustering tree to the clustering tree of the
normal performance.
There are two methods for determining the abnormal situation of
clustering tree, which are called respectively the comparison method
and the analysis method. The basic principle of comparison method is
now discussed next. First, a base of the clustering trees for
describing all normal states of operation of small telecommunication
network must be built, i.e., each clustering tree in this base
describes a normal status of operation of the network. Then, a special
algorithm is used to operate the current clustering tree and the
standard clustering tree at the same time for determining whether the
current clustering tree is normal. On the other hand, the basic
principle of analysis method is discussed as the following. In this
method, each node and arc in the current clustering tree is checked
for determining the abnormal node or arc so as to find out the
abnormal tree.
There are the various reasons to result in the abnormal clustering
tree. However, they are usually divided into two classes, the hard
reason and the soft reason. Further, the hard reason describes the
fault of elements in the infrastructure of small telecommunication
network. In general, this fault is physical, and can be not eliminated
though changing the decision of operation of small telecommunication
network. Otherwise, the soft reason is not physical, and can be
eliminated though changing the operation decision. Further, our
research shows that there are a number of the faults about the soft
reason in the current and future ATM networks. In fact, the abnormal
clustering trees generated from the two reasons are called
respectively the hard abnormal clustering tree and the soft abnormal
clustering tree. For the simplicity of this paper, some details of the
abnormal clustering tree about the hard and soft reasons is not
discussed here. However, this problem is easily solved by an overlay
principle. In the operation of existing small telecommunication
network, a number of problems are about the recovery of soft abnormal
clustering tree. In general, the soft abnormal clustering tree relates
close to the performance of the delay time and throughput of small
telecommunication network.
The method of transforming the soft abnormal clustering tree to
the normal clustering tree is to adjust the distribution of
information flow in the infrastructure of small telecommunication
network. Further, this method is really to adjust the mode of resource
use in small telecommunication network so that the abnormal clustering
tree is transformed into the normal clustering tree. Because the
status of information flow in small telecommunication network is fast
variable, this adjustment has the obvious requirement for the
performance of real time, i.e., the speed of adjustment must be very
fast. On the other hand, the control action of this adjustment has
obviously the character of delay. Otherwise, this adjustment is
different from the other common control action, which is a pulse
control of short time action. In the most situations, some standard
recovery procedures can be constructed for recovering various soft
abnormal clustering tree. Thus, a base of standard recovery procedures
can be also constructed for recovering fast and simply the soft
clustering tree.
The management of clustering tree in the above discussion is really
a feedback control method for managing the telecommunication network.
However, a number of statistical analyses for the information flow in
telecommunication network have shown that a feedforward control method
for managing the clustering tree or small telecommunication network
may be more satisfactory sometimes. The major principle of the
feedforward control method can be simply discussed next. First, a
number of the patterns of information flow in small telecommunication
network can be built with the help of some statistical rules from a
number of statistical analyses. Then, these patterns of information
flow are used to design various effective control methods for managing
the clustering tree of small telecommunication network, so that the
real time control of the operation of small telecommunication network
is effectively implemented. Otherwise, our research shows also that
this feedforward control method is more suitable to future ATM
networks. However, how to construct the statistic rule of information
flow in small telecommunication network is a very complex problem. The
key for solving this problem is how to recognize the patterns of
information flow from collecting a lot of statistical data. Here, we
suggest an effective method, called the multi-dimensions method, for
describing and constructing the patterns of information flow. This
method thinks that a four-dimensional space, which consists of time,
date, month and year, can be effectively used to describe the patterns
of information flow in small telecommunication network. Thus, a
typical pattern of the information flow can be represented as the
IFM=g(T, D, M, Y). Obviously, the g may be a very complex function.
However, in the many situations, the g can be described as a linear
function of combination of T, D, M, and Y, so that we can use the
IFM=g(T, D, M, Y) to describe the information flow in the node and arc
of clustering tree. On the other hand, the spatial operation about the
g(T, D, M, Y) can easily implemented in PC ARC/INFO.
In general, the implementation of some key techniques of the above
discussion is very easy. Especially, the special macro language of PC
ArcInfo can be used to design various program modules for
implementing various operations, e.g., generating, comparing and
diagnosing the clustering tree. Fortunately, there is a special
network function module in PC ARC/INFO, so that the implementation of
the above operations will be very easier.
4.TYPICAL ANALYSIS OF GRAPHIC MODEL
In order to discuss deep some typical processes of operation of
the graphic model for the operation management of small
telecommunication network, we will introduce two examples for showing
how to optimize the performance of small telecommunication network and
how to recognize its faults. Otherwise, we will also discuss the
problem how to design the method for optimizing the performance of
small telecommunication network.
1)The performance optimization of small telecommunication network:In
fact, the performance optimization is a very important task for
operating small telecommunication network with the help of the real
time management system of network. The goal of this optimization
includes the improvement of the real time performance and the
throughput performance of the network. Further, suppose the normal
clustering tree of the current small telecommunication network be TN0
and the practical clustering tree be TN0'. The average delay time of
N0 about the TN0 is t(TN0). The value of computation of the average
delay time of TN0' is t(TN0') by fast algorithm. On the other hand,
the throughput of TN0 is h(TN0), and the throughput of TN0 is h(TN0).
Further, if the difference between t(TN0) and t(TN0) and the
difference between h(TN0) and h(TN0') are larger than the given values
a0 and b0, respectively, then the optimization of the clustering tree
TN0 must be executed. In general, the methods for implementing the
performance optimization include usually the physical optimization and
the logical optimization, which are discussed respectively as the
following.
(1)Physical optimization:First, the TN0' is divided into several sub-
clustering trees so as to recognize the minimum sub-trees which result
in the abnormal TN0'. Then, these sub-trees are improved by the
redundant capacity of nodes and links of N0, so that these sub-trees
recover the normal status. Thus, the process of the physical
optimization has been implemented.
(2)Logical optimization:First, as the same as the above discussion,
the TN0' is divided into several sub-clustering trees so as to
recognize the minimum abnormal sub-trees. Then, some tables of
resource about the sub-trees, including the tables of resource of
various links and nodes of N0, are adjusted to recover the abnormal
sub-trees and to implement the logical optimization.
However, after the optimization is completed, the observation of
these past abnormal sub-trees must be continuous, so that the assigned
physical and logical resource must be collected when the abnormal
status of these sub-trees elapses. Otherwise, if the abnormal status
of these sub-trees exists forever, the substantial optimization or
fault diagnosis of these sub-trees must be begun(Zesheng, 1990).
2)Recognition of the faults of network:From the above analysis, we can
see that the recognition of the network faults in N0 is really
implemented by the management of the clustering tree. The process
relevant to this recognition is simply given as the following. The
occurrence of network faults results in the variation of distribution
of information flow in the network. Thus, after a series of sub-
clustering trees about the abnormal clustering tree TN0' are analyzed
and recognized, we can determine the sub-clustering trees which result
in the abnormal clustering tree. Then, a special relationship between
these clustering trees and the physical elements of the network can be
used to determine the practical position of network fault. There are
two typical network faults which are considered in our graphic model,
i.e., the hard fault and the soft fault. Further, the former fault is
mainly relevant to the hardware fault of the network, the latter is
mainly to the operation decision and the software fault of the
network. Obviously, the performance optimization and the fault
diagnosis all are relevant to the determination of the minimum
abnormal sub-clustering trees which result in the abnormal status of
TN0. In order to determine whether the abnormal sub-trees are relevant
to the performance optimization or the fault diagnosis, an algorithm
for identification of these sub-trees must be designed to implement
this goal.
3)Operation Decision for Optimization
As the above discussion, the decision for optimizing the operation
of small telecommunication network is really the decision for the
performance optimization of the management of small telecommunication
network TN0, and this process can be easily implemented by PC
ArcInfo.
The various decision for optimizing the operation of small
telecommunication network are provided by the pattern generator of the
network operation and are also affected by the feedback control for
the operation status of small telecommunication network. The small
telecommunication network N0 is really controlled by the double
mechanisms, including the feedforward and feedback controls. Our
experience on a prototype based on PC ARC/INFO has shown that the
performance of application of this control method is very
satisfactory. Especially, this control method will have the wider
areas of application in future ATM networks. The monitor module of N0
supports the interaction between the network and its manager. The
operation of all the above modules is supported by the environment of
PC ARC/INFO. A better plan of research is that the various patterns
about the operation management of small telecommunication network are
included in a knowledge base with the AI technique, and the clustering
trees are managed by the knowledge base and AI techniques.
4)Current Results on our Experiment
In the current time, the special GIS software-Esri's PC ARC/INFO -
is being used to develop various key techniques of the above
discussion and to construct a prototype of the real time management
system for operating the small telecommunication network. Some
practical and simulation experiments are carried out. The application
of GIS and the graphic model for the management makes the task of the
real time management of the operation of small telecommunication
network simpler and easier. All the experience shows that this graphic
model has the better performance than the other common model. Further,
some obvious advantages of the graphic model are discussed as the
following.
(1)Increase of the real time performance of the operation and
management of small telecommunication network;
(2)Easier evaluation of the operation quality of the network with the
uniform view;
(3)Easier visual operation for the operation management of the network
in GIS environment;
(4)Easier implementation of the performance optimization and the fault
diagnosis of the network;
(5)Easier construction of the user interface for the management;
(6)Easier application of AI technique in the real time management of
the network operation.
5.CONCLUSION
In this paper, we have discussed a method for building and
implementing the real time management system for operating the small
telecommunication network. The some keys of this method includes the
construction of management model based on the clustering tree, the
graphic modelling of the problem of the operation management of
network and the implementation of the graphic model in the environment
of GIS. Obviously, this clustering tree model provides an uniform view
to describe the operation management of network, and a powerful tool
for managing the network. On the other hand, the graphic interface and
spatial operation ability of GIS provide an excellent support with the
implementation of this model.
However, there are many problems to be researched in the future,
including the deeper analysis and research of the relationship between
the clustering tree and its special action of the network. On the
other development, a special module in PC ARC/INFO for operating the
tree data structure or graphic must be developed in the future so as
to make the fast operation of the graphic model. Otherwise, some
excellent tools of GIS, e.g., Esri's ARC View.2, will make the
construction of our system more reasonable and the implementation of
it easier. The other analysis and testing work on our prototype is
doing in the current time.
6.ACKNOWLEDGE
Many colleagues provide a lot of help with our research.
Especially, we would thank telecommunication engineering department
and the agricultural information research center for many helps and
warm research environment.
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Sun Ling
A. Reseacher, JiangSu Academy of Agricultural Sciences
JiangSu Academy of Agricultural Sciences
Nanjing, JiangSu, 210014, P. R. China
Telephone:86-025-4431481-325
Fax:86-025-4432691