The mobile handset, in terms of its design and functionality, must satisfy three distinct
sets of requirements . These relate to the network operators, the endusers,
and the handset vendors themselves. The requirements of the end user will often focus
on features and capabilities, and the overall ease of use (usability), and of course, the end user would like maximum functionality for minimum cost. Increasingly, the aesthetic
appeal of the handset is important as it evolves from the functional devices of
early handsets to fashion items that a user may wish to change every 12 to 18 months.
Although users often look for complex feature sets in handsets, research indicates that
a typical user frequently uses only 15 to 20 percent of the phone’s capabilities.
For a network operator the handset represents the front end of the network and
is the platform through which users gain access to the rich set of services offered.
This again means feature sets and capabilities, and the ease of use is critical. The
network operator is also very interested in handset cost because in many markets
the handset is still subsidized by the operators, and therefore they bear some of the
real handset costs.
Handset vendors are increasingly asked to provide evermore complex devices
that are smaller and lighter than their predecessors yet cost no more or even less.
The overall cost of the actual handset components is further complicated by the
issue of technology licensing. A current 3G phone will contain many noncellular
technologies, such as video codecs and picture compression algorithms, for which
a license fee is payable to third-party innovators. Another major issue for handset
vendors is brand maintenance; in the mind of the enduser, the phone may become
associated with the network and not the original handset manufacturer, and the
manufacturers expend a lot of effort in keeping their brand profile high.
The requirement to satisfy the sometimes-conflicting requirements of all parties
means that the market for handsets has inevitably fragmented in terms of device
capability and form factor. The devices produced for the prepay segment are very
different from those aimed at the high end of the market.
Original Equipment and Device Manufacturers
In the area of manufacturing — and mobile handsets are no exception — the topic
of original equipment manufacturers (OEMs) will normally surface. An OEM
is a manufacturing company that produces components or sometimes
complete pieces of equipment to the specifications and design of another company,
the value-added reseller (VAR).
The VAR will either take components from one or
more OEMs and integrate these into a system, or take an entire OEM assembly and
repackage it. The level of repackaging might be as basic as relabeling products to
adding greater value (e.g., software and other elements).
Batteries
The handset battery is an essential component and is one of the largest contributors
to the total weight and volume of the final product. It represents the balance
between the competing demands of supplying energy and being as light and small
as possible.
There are many processes within the mobile handset that are relatively energy
hungry. These include the radio circuits, the processing for voice and
multimedia signals, and the display. Various techniques are deployed both within
the handset and in the specifications of the radio technology that aim at reducing
energy consumption and therefore lengthening the life of the battery.
Although battery technology has come a long way since the early days of mobile
networks, it can take up to ten years for a battery technology to proceed from concept
to being fully commercially available.
Wednesday, July 4, 2007
Operational and Business Support Operational Support System (OSS)
The Requirements
Support for the operational network must be comprehensive in terms of structure
and procedures, and also in terms of systems and software tools. Broadly speaking,
the requirement can be split into three main areas:
1. Network management deals with managing the operational network, including
infrastructure, maintenance, and fault handling. The requirement is wide ranging,
allowing the complete network to be viewed in overview, or detail, with network
elements being handled remotely to keep the network running smoothly.
2. The customer service system allows for effective customer relations, covering
areas such as new orders, billing queries, and technical issues. The requirement
is easy to identify, and systems could be dedicated to this role, or be
fully integrated within a wider operational support system. In either case, information
must be available to the customer service representatives, relying on
good data interfaces between related functions (for example, customer billing
records need to be available to the customer service representative).
3. Other requirements can be grouped under the heading of business management
and include sales and marketing functions, finance, personnel, and
logistics, and a wide range of others.
Support for the operational network must be comprehensive in terms of structure
and procedures, and also in terms of systems and software tools. Broadly speaking,
the requirement can be split into three main areas:
1. Network management deals with managing the operational network, including
infrastructure, maintenance, and fault handling. The requirement is wide ranging,
allowing the complete network to be viewed in overview, or detail, with network
elements being handled remotely to keep the network running smoothly.
2. The customer service system allows for effective customer relations, covering
areas such as new orders, billing queries, and technical issues. The requirement
is easy to identify, and systems could be dedicated to this role, or be
fully integrated within a wider operational support system. In either case, information
must be available to the customer service representatives, relying on
good data interfaces between related functions (for example, customer billing
records need to be available to the customer service representative).
3. Other requirements can be grouped under the heading of business management
and include sales and marketing functions, finance, personnel, and
logistics, and a wide range of others.
The Role of CAMEL
CAMEL has been specified to allow operator-specific services (IN services) to be
provided for subscribers even while roaming abroad. The service control point
(SCP) is generally located in the home network, allowing serving network switches
to interact with it to provide the advanced services.
CAMEL is an acronym for Customized Applications for Mobile networks
Enhanced Logic, and has been specified to allow for the introduction of IN
services in mobile networks alongside both call control functions and mobility
management.
In the later phases of CAMEL, it also allows for the provision of advanced
services in support of GPRS, SMS, and supplementary services. The interfaces
required for CAMEL are standardized to a high degree, allowing network elements
from different networks to work together using the CAMEL Application
Part (CAP) message set of Signaling System Number 7 (SS7). An example CAMEL
procedure is shown in Figure 3.47 for clarity.
The aim is to allow Intelligent Network interactions with a service control point
located in the subscriber’s home network. CAMEL takes account of mobile originated,
mobile terminated, and mobile forwarding cases, and also allows for both
roaming and non-roaming cases.
Modifications at the MSC essentially give the switch the ability to recognize the
requirement for a CAMEL-based service and build the required messages for the
specified SCF. In addition, both the HLR and VLR must be modified to hold the
relevant CAMEL subscriber details.
CAMEL has been defined in different phases to allow a staged approach to
implementation. Each phase is a superset of the previous one. Not all networks will
be at the latest phase of CAMEL, or even support CAMEL at all — but in many
networks, CAMEL is used to support prepaid services.
provided for subscribers even while roaming abroad. The service control point
(SCP) is generally located in the home network, allowing serving network switches
to interact with it to provide the advanced services.
CAMEL is an acronym for Customized Applications for Mobile networks
Enhanced Logic, and has been specified to allow for the introduction of IN
services in mobile networks alongside both call control functions and mobility
management.
In the later phases of CAMEL, it also allows for the provision of advanced
services in support of GPRS, SMS, and supplementary services. The interfaces
required for CAMEL are standardized to a high degree, allowing network elements
from different networks to work together using the CAMEL Application
Part (CAP) message set of Signaling System Number 7 (SS7). An example CAMEL
procedure is shown in Figure 3.47 for clarity.
The aim is to allow Intelligent Network interactions with a service control point
located in the subscriber’s home network. CAMEL takes account of mobile originated,
mobile terminated, and mobile forwarding cases, and also allows for both
roaming and non-roaming cases.
Modifications at the MSC essentially give the switch the ability to recognize the
requirement for a CAMEL-based service and build the required messages for the
specified SCF. In addition, both the HLR and VLR must be modified to hold the
relevant CAMEL subscriber details.
CAMEL has been defined in different phases to allow a staged approach to
implementation. Each phase is a superset of the previous one. Not all networks will
be at the latest phase of CAMEL, or even support CAMEL at all — but in many
networks, CAMEL is used to support prepaid services.
Intelligent Networks and CAMEL
Introduction to Intelligent Networks (INs)
Traditionally, switching equipment (telephone exchanges) would need upgrading
each time a new service was added to the network (Figure 3.42). In some networks,
the presence of hundreds or thousands of telephone exchanges meant that this was
a very long and labor-intensive task.
The concept of Intelligent Networks (INs) allows the service to be provided
within a central computer or service control point (Figures 3.43). Once the telephone
exchanges have been upgraded to include the IN features, no further upgrades are
required except for the updating of the tables that identify the IN triggers, such as
the 1-800- or 0800-digit string to identify the toll-free or freephone service.
These services are generally provided through service control points, which
translate the service-specific dialed numbers (an 800 number perhaps) into standard
numbers for routing to the actual destination (telephone) in the network.
The special number is the initial trigger for the telephone exchange to contact the
service control point, to translate the number, and to carry out special billing, such
as reverse charging or collect calls, or premium rate.
These early services were soon followed by further advanced services based on
the intelligence or control features within the service control point. Extra service
features such as interaction with the user allow further customization of services.
IN separates service intelligence and switching. This means that new services
can be quicker and cheaper to install, and that service creation and switching is
split into two markets, thereby increasing vendor competition.
Most IN, including GSM Phase 2+ networks, use SS7 (Signaling System Number
7) protocols to enable the switches (known as service switching points, or SSPs)
to communicate with databases known as service control points (SCPs). A standardized
set of SS7 messages known as INAP (Intelligent Network Application
Part) is used for interaction between the SSP and SCP.
The intelligent applications that control IN services are defined by the operator,
and are not themselves standardized. This means that IN offers a route to operator
differentiation, but also that in many cases the same services cannot be offered
outside the network of that operator.
Service Control Platforms
Service control platform (SCP) is the name given to a platform that is, in some way,
controlling services on a network, or in some cases, across network boundaries. One
of the main advantages in using an SCP within a network is that it significantly
reduces the upgrade costs within a network whenever a new service is introduced.
Control of supplementary services. These may include services such as conference
calls, advice on billing, and provision of call-back services such as ring
back when free. Supplementary services are seen as key revenue generators for
network operators.
Number translation services. In most modern networks it is possible to dial tollfree,
local or premium rate services. These are, in effect, virtual numbers that
have special tariffs. Number translation services (NTS) minimize the amount
of configuration required on the network when a new service is provided.
CAMEL (Customized Applications for Mobile Networks Enhanced Logic)
INs and Mobile Networks: The Problems
In fixed networks, the IN concept can be implemented in various ways.
In each case, however, the interfaces are confined within a single network, allowing
the defined procedures and information flows to be applied on an interface
with known and defined endpoints, and within hardware belonging to the single
network operator.
Testing is therefore more straightforward as each interface can be tested independently
and, in addition, non-standard procedures and information can be used
to satisfy particular problems (even if this is just a certain way of interpreting an
ambiguous part of the standards). The IN procedures have been specified to interwork
(mainly) with call control, hence a simple relationship exists between the two.
For mobile networks, the situation is more complex because roaming scenarios
require that equipment in more than one network is involved. Considering
all the roaming agreements each network will have in place, and the rapid change of each of these networks as new hardware (switches, etc.) is added, it is
impossible to test each individual interface that will likely be involved in an IN call,
or to interpret specifications in anything other than a single standard way.
The next big complication is that IN procedures need to interwork with call
control, mobility management functions, and the additional features of mobile
networks such as the General Packet Radio Service and the Short Message
Service. Finally, any announcements should be supported by special announcement
machines, the positioning of which needs careful thought. Location in the
home network provides ease of management, but an international call leg would
be needed to play announcements to roaming subscribers. Locating the announcement
machines in serving networks leads to a higher cost of hardware and increased
management costs, but reduced cost per call.
Traditionally, switching equipment (telephone exchanges) would need upgrading
each time a new service was added to the network (Figure 3.42). In some networks,
the presence of hundreds or thousands of telephone exchanges meant that this was
a very long and labor-intensive task.
The concept of Intelligent Networks (INs) allows the service to be provided
within a central computer or service control point (Figures 3.43). Once the telephone
exchanges have been upgraded to include the IN features, no further upgrades are
required except for the updating of the tables that identify the IN triggers, such as
the 1-800- or 0800-digit string to identify the toll-free or freephone service.
These services are generally provided through service control points, which
translate the service-specific dialed numbers (an 800 number perhaps) into standard
numbers for routing to the actual destination (telephone) in the network.
The special number is the initial trigger for the telephone exchange to contact the
service control point, to translate the number, and to carry out special billing, such
as reverse charging or collect calls, or premium rate.
These early services were soon followed by further advanced services based on
the intelligence or control features within the service control point. Extra service
features such as interaction with the user allow further customization of services.
IN separates service intelligence and switching. This means that new services
can be quicker and cheaper to install, and that service creation and switching is
split into two markets, thereby increasing vendor competition.
Most IN, including GSM Phase 2+ networks, use SS7 (Signaling System Number
7) protocols to enable the switches (known as service switching points, or SSPs)
to communicate with databases known as service control points (SCPs). A standardized
set of SS7 messages known as INAP (Intelligent Network Application
Part) is used for interaction between the SSP and SCP.
The intelligent applications that control IN services are defined by the operator,
and are not themselves standardized. This means that IN offers a route to operator
differentiation, but also that in many cases the same services cannot be offered
outside the network of that operator.
Service Control Platforms
Service control platform (SCP) is the name given to a platform that is, in some way,
controlling services on a network, or in some cases, across network boundaries. One
of the main advantages in using an SCP within a network is that it significantly
reduces the upgrade costs within a network whenever a new service is introduced.
Control of supplementary services. These may include services such as conference
calls, advice on billing, and provision of call-back services such as ring
back when free. Supplementary services are seen as key revenue generators for
network operators.
Number translation services. In most modern networks it is possible to dial tollfree,
local or premium rate services. These are, in effect, virtual numbers that
have special tariffs. Number translation services (NTS) minimize the amount
of configuration required on the network when a new service is provided.
CAMEL (Customized Applications for Mobile Networks Enhanced Logic)
INs and Mobile Networks: The Problems
In fixed networks, the IN concept can be implemented in various ways.
In each case, however, the interfaces are confined within a single network, allowing
the defined procedures and information flows to be applied on an interface
with known and defined endpoints, and within hardware belonging to the single
network operator.
Testing is therefore more straightforward as each interface can be tested independently
and, in addition, non-standard procedures and information can be used
to satisfy particular problems (even if this is just a certain way of interpreting an
ambiguous part of the standards). The IN procedures have been specified to interwork
(mainly) with call control, hence a simple relationship exists between the two.
For mobile networks, the situation is more complex because roaming scenarios
require that equipment in more than one network is involved. Considering
all the roaming agreements each network will have in place, and the rapid change of each of these networks as new hardware (switches, etc.) is added, it is
impossible to test each individual interface that will likely be involved in an IN call,
or to interpret specifications in anything other than a single standard way.
The next big complication is that IN procedures need to interwork with call
control, mobility management functions, and the additional features of mobile
networks such as the General Packet Radio Service and the Short Message
Service. Finally, any announcements should be supported by special announcement
machines, the positioning of which needs careful thought. Location in the
home network provides ease of management, but an international call leg would
be needed to play announcements to roaming subscribers. Locating the announcement
machines in serving networks leads to a higher cost of hardware and increased
management costs, but reduced cost per call.
BREW (Binary Runtime Environment for Wireless)
BREW is also seen as an ecosystem. It has been associated mainly with cdma-based
systems; however, technically, it is available for use with GSM/GPRS and UMTS
networks — that is, it is mobile technology agnostic.
BREW provides a whole range of features, applications, and services that can
be accessed by the user via the BREW software on the handset. BREW application
developers are provided with the development and testing tools they need to make
the applications available to the users. Operators benefit from a flexible system that
provides a platform for a variety of advanced services and features.
The BREW distribution system (BDS) is the network-based system that distributes
the content and applications.
systems; however, technically, it is available for use with GSM/GPRS and UMTS
networks — that is, it is mobile technology agnostic.
BREW provides a whole range of features, applications, and services that can
be accessed by the user via the BREW software on the handset. BREW application
developers are provided with the development and testing tools they need to make
the applications available to the users. Operators benefit from a flexible system that
provides a platform for a variety of advanced services and features.
The BREW distribution system (BDS) is the network-based system that distributes
the content and applications.
Messaging Platforms
Voicemail Platforms
While voicemail appears to be a very simple service to provide to customers,
the fact is that it is an extremely important platform for operators — especially in
terms of revenue generation.
First, any call that is answered by a voicemail announcement is technically
terminated. All of the networks involved in the delivery of the call will receive
revenue. Second, on receipt of a voicemail message, many users will return the call,
generating yet further revenue for the operators.
In many cases, basic voicemail services are provided free of charge or included
in the monthly tariff. However, operators can charge a premium for premium
voicemail services, where the user is able to keep messages stored for a longer
period. Combining voicemail with calling line ID, operators can provide a service
that allows the user to call the person who left the message by pressing a single
key.
Short Message Service SMS
SMS allows for the exchange of short alphanumeric messages between a mobile
station and an SMS service center (SMSC). The messages can be either mobile
terminated
(from SMSC to mobile) or mobile originated (from mobile to SMSC). Of
course, in most SMS interactions, the mobile originated service is followed almost
immediately by the mobile terminated service (of the same message, but different
users). Messages are limited to 160 characters (depending on the language used).
Mobile Terminated Point-to-Point
These messages are sent from an SM service center (Figure 3.37) to a mobile station.
Upon receipt of the message, the mobile station will return a confirmation to
the SM service center. The message may be received when the mobile is not being
used, or even while it is being used for a voice call.
Mobile Originated Point-to-Point
Here the message is from the mobile to the SM service center, and a confirmation of
receipt (not necessarily delivery) is given. The generally accepted problem of mobile
originated SMS is the inputting of the text to the phone, which can be a slow and
laborious process. One increasingly popular short-cut is to edit the message on a
computer, laptop, or PDA (personal digital assistant) and then transfer the message
to the phone. On mobile phones themselves, intelligent text recognition software is
becoming increasingly sophisticated.
Enhanced Messaging Service (EMS)
An extension of SMS, EMS allows ringtones, operator logos, and other simple visual
images and icons to be sent to compatible devices. Pictures, sounds, animation, and
text can be sent to a device in an integrated package. No modification of the SMSC
is necessary because EMS uses the User Data Header (UDH) that is already present
in SMS messages. However, EMS-compatible handsets are required. The EMS
standard is included as part of the standard 3GPP feature set.
SMS Cell Broadcast
The SMS cell broadcast service transmits the same message to all mobiles within
a particular cell (or group of cells). The message limit in this case is 93 characters,
and the mobile must be in idle mode to receive the message. No acknowledgment
of receipt is given. Cell broadcast does not generate revenue because broadcast messages,
which offer no confirmation of receipt, cannot be charged. They tend, therefore,
to be seen as a value-added feature to attract customers. Uses might include
advertising (e.g., other network features) or the broadcasting of PSTN local area
codes such that a mobile user is able to distinguish between local and long-distance
calls (tariffs may vary between the two).
The Multimedia Messaging Service (MMS)
MMS is a non-real-time service, often seen as a natural progression from the GSM
Short Message Service. Like SMS, messages can be stored before being forwarded
to the recipient whenever they are available or they request to see the message. It
combines different networks and integrates messaging systems that already exist in
these networks, for example, SMS in GSM and so-called “Instant Messaging” via
the Internet.
MMS is designed to support either standard e-mail addresses or standard ISDN
telephone numbers; and WAP (Wireless Application Protocol) development also
provides significant support for MMS.
The user terminal operates in the Multimedia Messaging Service Environment
(MMSE). MMSE provides the service elements such as delivery, storage, and
notification, which may be located in one network or distributed across different
networks.
The basis of connectivity between the networks is provided by IP (Internet Protocol)
and its associated set of messaging protocols, enabling compatibility between
2G and 3G wireless messaging and Internet messaging.
While voicemail appears to be a very simple service to provide to customers,
the fact is that it is an extremely important platform for operators — especially in
terms of revenue generation.
First, any call that is answered by a voicemail announcement is technically
terminated. All of the networks involved in the delivery of the call will receive
revenue. Second, on receipt of a voicemail message, many users will return the call,
generating yet further revenue for the operators.
In many cases, basic voicemail services are provided free of charge or included
in the monthly tariff. However, operators can charge a premium for premium
voicemail services, where the user is able to keep messages stored for a longer
period. Combining voicemail with calling line ID, operators can provide a service
that allows the user to call the person who left the message by pressing a single
key.
Short Message Service SMS
SMS allows for the exchange of short alphanumeric messages between a mobile
station and an SMS service center (SMSC). The messages can be either mobile
terminated
(from SMSC to mobile) or mobile originated (from mobile to SMSC). Of
course, in most SMS interactions, the mobile originated service is followed almost
immediately by the mobile terminated service (of the same message, but different
users). Messages are limited to 160 characters (depending on the language used).
Mobile Terminated Point-to-Point
These messages are sent from an SM service center (Figure 3.37) to a mobile station.
Upon receipt of the message, the mobile station will return a confirmation to
the SM service center. The message may be received when the mobile is not being
used, or even while it is being used for a voice call.
Mobile Originated Point-to-Point
Here the message is from the mobile to the SM service center, and a confirmation of
receipt (not necessarily delivery) is given. The generally accepted problem of mobile
originated SMS is the inputting of the text to the phone, which can be a slow and
laborious process. One increasingly popular short-cut is to edit the message on a
computer, laptop, or PDA (personal digital assistant) and then transfer the message
to the phone. On mobile phones themselves, intelligent text recognition software is
becoming increasingly sophisticated.
Enhanced Messaging Service (EMS)
An extension of SMS, EMS allows ringtones, operator logos, and other simple visual
images and icons to be sent to compatible devices. Pictures, sounds, animation, and
text can be sent to a device in an integrated package. No modification of the SMSC
is necessary because EMS uses the User Data Header (UDH) that is already present
in SMS messages. However, EMS-compatible handsets are required. The EMS
standard is included as part of the standard 3GPP feature set.
SMS Cell Broadcast
The SMS cell broadcast service transmits the same message to all mobiles within
a particular cell (or group of cells). The message limit in this case is 93 characters,
and the mobile must be in idle mode to receive the message. No acknowledgment
of receipt is given. Cell broadcast does not generate revenue because broadcast messages,
which offer no confirmation of receipt, cannot be charged. They tend, therefore,
to be seen as a value-added feature to attract customers. Uses might include
advertising (e.g., other network features) or the broadcasting of PSTN local area
codes such that a mobile user is able to distinguish between local and long-distance
calls (tariffs may vary between the two).
The Multimedia Messaging Service (MMS)
MMS is a non-real-time service, often seen as a natural progression from the GSM
Short Message Service. Like SMS, messages can be stored before being forwarded
to the recipient whenever they are available or they request to see the message. It
combines different networks and integrates messaging systems that already exist in
these networks, for example, SMS in GSM and so-called “Instant Messaging” via
the Internet.
MMS is designed to support either standard e-mail addresses or standard ISDN
telephone numbers; and WAP (Wireless Application Protocol) development also
provides significant support for MMS.
The user terminal operates in the Multimedia Messaging Service Environment
(MMSE). MMSE provides the service elements such as delivery, storage, and
notification, which may be located in one network or distributed across different
networks.
The basis of connectivity between the networks is provided by IP (Internet Protocol)
and its associated set of messaging protocols, enabling compatibility between
2G and 3G wireless messaging and Internet messaging.
The Virtual Home Environment (VHE) Concept
In the VHE , users are consistently presented with the same personalized
features, user interface, customization, and services — in whatever network
they are located, or terminal they may be using (assuming that capabilities in the
network and terminal exist).
In defining the VHE, it is useful to introduce the concept of the home environment.
This can be synonymous with the user’s home network and subscribed
services, but can also include other value-added service providers (VASPs), which
are accessed through this home network service provider. The home environment
provides (and controls) the personal service environment in association with the
user’s own personal profile.
The serving network describes the network to which the user is attached at
the time, and thus may be a network in which they are roaming (when traveling
abroad). In the VHE concept, this network should be invisible to the user, with services
transported seamlessly. It may be another mobile network, but could equally
also be applied to a fixed network, the Internet, etc., depending how the users
choose to access their services at any one time.
VHE also takes into account the possibility of value-added service providers, who
may be part of neither the home nor the serving environment. For example, a banking
service may be provided directly from a bank VASP. Users should still be able to
transparently access these services whether or not they are in their home network.
Location Platforms
3G systems (including UMTS) are designed from the outset to provide for accurate
location of user equipment (mobile handsets), and this allows for providing
advanced location-based services. The location information is collated and managed
by location platforms (primarily the serving mobile location center and the gateway
mobile location center). This information can then be accessed and used by the
service platform in a variety of different services.
In UMTS, the location determination can be achieved in three main ways (discussed
shortly), and may also be provided as part GSM or GPRS.
The location information can be used by the PLMN operator, emergency services,
value-added service providers, and for lawful interception by authorized
agencies. The PLMN could use location information for a variety of purposes,
including handover optimization. Emergency services can radically improve the
overall response time if automatic mobile terminal location is provided. Valueadded
services can be significantly enriched and in some cases enabled — for
example, downloading a map showing where the subscriber is and how to reach a
local address.
The quality of location information is defined in terms of horizontal accuracy
(10 to 100 meters, according to the application), vertical accuracy (up to 10 meters),
and response time (no delay, low delay, or delay-tolerant criteria). It can also be
defined by priority (e.g., emergency services have highest priority), time stamping
(vital for some applications such as lawful interception), security measures (to
ensure controlled access to user location information), and privacy.
features, user interface, customization, and services — in whatever network
they are located, or terminal they may be using (assuming that capabilities in the
network and terminal exist).
In defining the VHE, it is useful to introduce the concept of the home environment.
This can be synonymous with the user’s home network and subscribed
services, but can also include other value-added service providers (VASPs), which
are accessed through this home network service provider. The home environment
provides (and controls) the personal service environment in association with the
user’s own personal profile.
The serving network describes the network to which the user is attached at
the time, and thus may be a network in which they are roaming (when traveling
abroad). In the VHE concept, this network should be invisible to the user, with services
transported seamlessly. It may be another mobile network, but could equally
also be applied to a fixed network, the Internet, etc., depending how the users
choose to access their services at any one time.
VHE also takes into account the possibility of value-added service providers, who
may be part of neither the home nor the serving environment. For example, a banking
service may be provided directly from a bank VASP. Users should still be able to
transparently access these services whether or not they are in their home network.
Location Platforms
3G systems (including UMTS) are designed from the outset to provide for accurate
location of user equipment (mobile handsets), and this allows for providing
advanced location-based services. The location information is collated and managed
by location platforms (primarily the serving mobile location center and the gateway
mobile location center). This information can then be accessed and used by the
service platform in a variety of different services.
In UMTS, the location determination can be achieved in three main ways (discussed
shortly), and may also be provided as part GSM or GPRS.
The location information can be used by the PLMN operator, emergency services,
value-added service providers, and for lawful interception by authorized
agencies. The PLMN could use location information for a variety of purposes,
including handover optimization. Emergency services can radically improve the
overall response time if automatic mobile terminal location is provided. Valueadded
services can be significantly enriched and in some cases enabled — for
example, downloading a map showing where the subscriber is and how to reach a
local address.
The quality of location information is defined in terms of horizontal accuracy
(10 to 100 meters, according to the application), vertical accuracy (up to 10 meters),
and response time (no delay, low delay, or delay-tolerant criteria). It can also be
defined by priority (e.g., emergency services have highest priority), time stamping
(vital for some applications such as lawful interception), security measures (to
ensure controlled access to user location information), and privacy.
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