Issue: 12
February 2008
Telecommunications
Regulatory Authority
Decision No: 6/2009
Technical Quality of
Service and Key Performance Indicators Regulation
The TRA, during its meeting
held on 18/03/2009
Pursuant to law No 431 dated 22/07/2002
(Telecommunications Law), in particular Article 25,
Pursuant to Decree No 14264 dated 4/03/2005
(Financial and administrative management of the Telecommunications Regulatory
Authority),
Pursuant to Decree No 1 dated
08/02/2007 (Appointment of the TRA Board),
And upon the advice of the Council
of State (Opinion No. 41/2008-2009 dated 29/01/2009),
Issued the following regulation:
1.
This Technical Quality of Service (QoS) & Key Performance Indicators
(KPI) Regulation (the Regulation) forms part of the regulations issued by the
Telecommunications Regulatory Authority (the Authority) of Lebanon in
accordance with the Telecommunications Law Law No. 431 of 2002
(Telecommunications Law). This Regulation is designed to serve potential and
current market participants in the telecommunications sector by providing clear
and concise explanations concerning all technical elements of QoS and KPI.
2.
This Regulation is a binding regulation that states the official
policies and procedures of the Authority. It may be subject to review and
amendment as deemed necessary by the Authority in light of the development of
the Lebanese telecommunications market, changes to Lebanese national laws
impacting the telecommunications sector, or other factors.
1.
The Telecommunications Law grants the Authority the power to issue
regulations pertaining to competition, quality of service, interconnection,
dispute resolution, pricing, consumer affairs, spectrum and any matter which
the Authority deems necessary to implement the Telecommunications Law.
2.
To that end, Article 25 of the Telecommunications Law addresses specific
responsibilities of the Authority in matters related to Technical QoS and KPI
and directs the Authority to ensure:
a. Any public telecommunications services license shall include mandatory and optional infrastructure expansion targets related to the scope of services, and standards that ensure high quality of service, as deemed appropriate by the Authority in the public interest.
b. QoS standards include, but are not limited to, requirements related to the service availability access delay, call completion rates, fault incidence and time to repair, dial tone delays and other faults that occur during the call.
c. The Authority shall establish procedures for standards, reporting and monitoring compliance with infrastructure expansion targets, and QoS standards.
1.
Individual clauses containing the word shall are mandatory
requirements and are binding on service providers.
2.
Individual clauses containing the word should are recommendations to
service providers but are not mandatory.
3.
Individual clauses containing the word may are permissions to service
providers.
1. The Authoritys principles
pertaining to the Technical QoS and KPI Regulation are based on the development
of a competitive environment. These principles are detailed in Appendix A of
this Regulation.
Through
this Regulation the Authority aims to assure consumers of quality service,
fairness in tariffs, and transparency in billing.
2. Specifically, the
Authority will ensure that all service providers shall take measures to ensure:
a.
billing accuracy;
b.
detailed and per service billing and charging;
c.
proper procedures for the resolution of customer disputes.
3. The Authority will ensure
that all services provided by service providers include requirements
concerning:
a. service availability;
b. QoS;
c. network performance.
4. This Regulation is
designed to define a minimum set of standards that service providers shall
meet; the Authority will ensure that these KPIs are regularly published to
assist users to make informed decisions as to their service provider(s).
1.
This Regulation applies to all service providers and users of public
telecommunications services in Lebanon.
It does not apply to users of private telecommunications services. The
service providers should undertake the changes to their systems and processes
allowing the application of this regulation. Service providers may request the Authority
to grant additional time to undertake the required changes.
2.
The attached annexes are deemed to be an integral part of this regulation, but the Annexes (a)
and (b) contain a scientific study about ITU recommendations and KPIs and do
not contain any binding provisions.
In the event of conflict or ambiguity between the terms defined herein
and the terms defined in a license or in the Telecommunications Law, then the
following order of precedence shall apply:
a. Telecommunications Law.
b. Technical QoS & KPI
Regulation.
c. Service provider license.
In this Regulation, the following terms shall have the corresponding
meanings:
Authority - the telecommunication
regulatory authority
Busy hour - the sliding 60-minute period
during which the maximum total traffic load occurs in a given 24-hour period.
The service provider is required to indicate the busy hour during which the
measurement is taken.
Consumer - any person,
other than a service provider, who is or may become a customer or user.
Emergency Services - the ability to connect in
priority, from any service area via any subscriber or public terminal or device
to national pre-defined numbers regardless of the subscription
validity. Emergency service obligations will be addressed in a separate
regulation by the TRA.
Network
Performance - The ability of a network portion to provide
the functions related to communication between users (ITU-T Rec. E.800).
Quality
of Service - The collective effect of service performance which determines the degree
of satisfaction of a user of the service. The level of quality required by the
users of a service may be expressed non-technically.
Service
Provider A Person that is licensed by the TRA to provide, directly
or indirectly, Telecommunications Services.
1. The parameters along with
corresponding target levels specified in Article 10
of this Regulation are mandatory minimum standards that service providers,
shall comply with. The Authority will publish by way of a decision, on an
annual basis, target levels for defined QoS and KPI parameters. The initial
parameters and corresponding target levels are those set out in Article 10 of this Regulation.
2. The QoS and KPI parameters
set in Article 10 may be amended from time to time, as the
Authority shall determine after due consultation, following the introduction of
new telecommunications technologies, or research performed by the Authority or
any other recognized national or international technical research institute, or
any other technical events that the Authority consider appropriate.
3. The target levels for QoS
and KPI parameters may be amended by the Authority from time to time taking
into account, inter alia, the level of competition in the market, the state of
development of the market, consumer complaints, technology developments or
other matters that the Authority may consider appropriate.
4. If a relevant market is
determined to be competitive pursuant to the SMP Regulation, then the QoS
targets for that market become recommendations instead of mandatory.
1.
There exist two generally accepted methods for a regulator to regulate
the QoS of a service provider:
a.
the traditional approach where QoS targets are set, against which
service provider performance is measured, followed by a system of penalties and
rewards based on those QoS targets; and
b.
the alternative approach where a QoS variable is incorporated in a price
cap formula as the Q-factor where lower quality leads to lower consumer prices,
while higher quality may lead to higher prices.
2.
Until further notice, the Authority will adopt the traditional approach
as described in paragraph (a) above, and will consult on the alternative
approach based on price cap before deciding on its adoption.
Fixed Network
Services |
|
QoS/Network
Performance Parameter |
Target Level |
Availability
of Telephone Exchange Equipment |
≥ 99.99% |
Call Set Up
Time (Post dialling delay to ring tone) |
≤ 3 seconds national at busy hour ≤ 8 seconds for international at busy hour |
Billing
Accuracy (valid accuracy-related complaints) |
≤ 3 complaints per 1000 bills |
Unsuccessful Call Ratio (% of call attempts) |
≤ 1% On-Net National at busy hour ≤ 2% International at busy hour |
Supply Time
for Connection |
90% within 3 working days |
Fault Rate per
Access Line |
≤ 3 failures per 100 lines per month |
Fault Repair
Time (except for outages reports outlined in Article 11) |
95% within 72 hours |
Response Time
for Operator Services (Time to answer from last digit dialled) |
90% within 15 seconds |
International
Voice Services |
|
QoS/Network
Performance Parameter |
Target Level |
Call Set Up
Time (Post dialling delay to ring tone) |
≤ 5 seconds for international |
Echo
Cancellers Usage at the Central Office |
≥ 99.9% of each International Gateway
Switch is using Echo Canceller for each Speech connection |
Total delay in
International Calls |
≤ 250 ms |
Unsuccessful Call Ratio (% of call attempts) |
≤ 2% International at busy hour |
Resolution time of International Gateway fault impacting traffic (except for outages reports outlined in Article 11) |
Within 1 hour |
Domestic Leased Line
Services |
|
QoS/Network
Performance Parameter |
Target Level |
Supply Time
for Connection |
≥ 90% completed on agreed day (as per the terms and conditions of the service) |
Fault Repair
Time (except for outage reports outlined in Article 11) |
95% within 24 hours |
Service
Availability |
≥ 99.70 |
International
Leased Line Services |
|
QoS/Network
Performance Parameter |
Target Level |
Service
Availability |
≥ 95% |
Fault Repair
Time (except for outages reports outlined in Article 11) |
90% within
agreed repair time |
Supply Time
for Connection |
90% completed on agreed day (as per the terms and conditions of the service) |
Mobile
Telecommunications Services |
|
QoS/Network
Performance Parameter |
Target Level |
Supply Time
for Connection |
On demand for pre paid and within 3 hours for post paid |
Call Set Up
Time (Post dialling delay to ring tone) |
5 seconds On-Net national at busy hour 10 seconds for international at busy hour |
Unsuccessful Call Ratio (% of call attempts) |
≤ 1% National at busy hour ≤ 2% International at busy hour |
Dropped calls Per Cell |
1 dropped call per 100 calls per Cell at busy hour |
Congestion Factor |
5 % of all Cells at busy hour |
SMS Mobile Originated/Terminated Delivered |
95% Delivered with 24 hours |
Average Time to Respond to Customer Calls |
85% of calls in less than 35 seconds |
Billing accuracy (valid accuracy related complaints) |
≤ 3 complaints per 1000 bills |
Fault repair time (except for outages reports outlined in article 11) |
95% within 72 hours. |
|
Wireless Data Services
(<2048 bit/s) |
||
|
QoS/Network Performance Parameter |
Target Level |
|
|
Service
Availability |
≥ 99.00% |
|
|
Supply Time
for Connection |
90% completed on agreed day (as per the terms and conditions of the service) |
|
|
Fault Repair
Time (except for outage reports outlined in Article 11) |
95% within 24 hours |
|
|
Ratio of
Packet Loss |
≤ 5% Packet Loss |
|
|
Round trip
Delay |
≤ 95 milliseconds (ms) for national
reference < 250milliseconds for International reference |
|
|
Jitter |
< 50milliseconds |
|
Wireless Broadband
Data Services (≥ 2048 bit/s) |
|||
QoS/Network Performance Parameter |
Target Level |
||
Service
Availability |
≥ 99.00% |
||
Supply Time
for Connection |
95% completed on agreed day |
||
Customer Fault
Rate per leased line |
1.25 failures per 100 customers per month |
||
Fault Repair
Time |
95% within
24 hours |
||
Ratio of
Packet Loss |
≤ 5% Packet Loss |
||
Round trip
Delay |
≤ 95 milliseconds (ms) for national
reference < 250 milliseconds (ms) for International
reference |
||
Jitter |
< 50 milliseconds |
||
Fixed Prepaid Card
Services |
|
QoS/Network Performance Parameter |
Target Level |
Debit Accuracy |
99.99 % |
Audio Text Services |
|
QoS/Network Performance Parameter |
Target Level |
Service Supply Time |
95% completed on agreed day |
Bill correctness
complaints |
3 complaints per 1000 bills |
Premium Charge Services |
|
QoS/Network Performance Parameter |
Target Level |
Service Supply
Time |
On demand |
Bill
correctness complaints |
3 complaints per 1000
bills |
Wireline Data Services |
|
QoS/Network Performance Parameter |
Target Level |
Dial-Up Call
Set Up Time (Post dialling delay to ring tone) |
1.9 seconds
national |
ADSL Service
Availability |
≥ 99% |
Unsuccessful Connect Ratio (per Number of call attempts) |
10 per 1000
attempts |
ADSL
Throughput x Kbits downstream / y Kbits upstream at busy hour |
Upstream 90% of time y kbits Downstream 90% of time x kbits |
Ratio of
Packet Loss |
≤ 5% Packet Loss |
Round trip
Delay |
< 95 milliseconds (ms) for national reference < 250 milliseconds for international reference |
Jitter |
< 50 milliseconds |
All service providers
shall provide the Authority with network outage reports whenever any outage
occurs as described in the clauses below.
1. Critical Outages are
defined as those affecting the entire network, the core of the network or
greater or equal to (=>) 30% of the traffic. The condition includes a
critical work stoppage during the customers normal working hours that affects
multiple sites or Core Network Elements affecting functions of a customers
business. Examples of Critical Outages
include, but are not limited to:
A. Mobile services:
outages affecting MSC/VLR, HLR/AUC, BSC, transmission (main hub or multiplexer
node of SDH/ PDH)
B. Fixed services: outages
affecting central offices serving more than 40,000 subscribers, transit
switches, international switches, Transmission (main hub or multiplexer node of
SDH/ PDH), fiber optic cable affecting the serving ring without redundancy,
Intermediate Data Rate Earth Stations, Layer2 Switches...
C. Internet services:
outages affecting core routers, the Network Operation Centers, International
Exchange Points, International Gateway
D. Data services: outages
affecting BRAS, core routers, International Exchange Points, DSLAMs, Layer2
Switches, Network Operation Center
2. Major Outages are defined
as those affecting a part of the network (or the components of the aggregate
part of the network), and influencing less than (<) 30% of the traffic.
Examples of Major Outages include, but are not limited to, outages affecting
the same network elements listed in clause 25 of this Regulation.
3. Minor Outages are defined
as those affecting individual sites, and/or components at the edge level of the
network that do not interrupt service or performance. Examples of Minor
Outages are those affecting BTS, trunk cable, or E1 transmission link.
1. Critical Outages shall be
repaired within one (1) hour. All service providers shall inform the Authority
immediately of such outages and shall submit to the Authority an outage report,
as per Appendix C, immediately after the problem is resolved and the service is
restored. In the event that a Critical Outage cannot be repaired in the
required period, a justification report shall be submitted to the Authority
immediately; the outage report shall then be submitted, as per Appendix C, when
the outage is repaired.
2. Major Outages shall be
repaired within four (4) hours. All service providers shall submit to the
Authority an outage report, as per Appendix C, within two (2) days. In the
event that a Major Outage cannot be repaired in the required period, a
justification report shall be submitted to the Authority immediately; the
outage report shall then be submitted, as per Appendix C, when the outage is repaired.
3. Minor Outages shall be
repaired within one (1) day. All service providers shall submit to the
Authority an outage report, as per Appendix C, within seven (7) days. In the
event a Minor Outage cannot be repaired in the required period, a justification
shall be attached to the outage report submitted to the Authority as per
Appendix C, when the outage is repaired.
4. Outages affecting
Emergency Services shall be repaired within thirty (30) minutes. All service
providers shall inform the Authority immediately of such outages and shall
submit to the Authority an outage report, as per Appendix C, immediately after
the problem is resolved and the service is restored. In the event an Emergency
Services Outage cannot be repaired in the required period, a justification
report shall be submitted to the Authority immediately; the outage report shall
then be submitted, as per Appendix C, when the outage is repaired.
1. The service provider shall
submit to the Authority, within one hundred and twenty (120) days from the date
of publication of this regulation in the Official Gazette, the schedule by
which he shall comply with his obligations under this Regulation. Full
compliance with the obligations according to this Regulation shall be complete
after one (1) year from the date from the date of publication of this regulation
in the Official Gazette.
2. Service providers shall
monitor their compliance on a monthly basis and shall report their findings on
a rolling basis to the Authority as follows:
ˇ
by the 15th day of April for the period January March,
ˇ
by the 15th Day of July for the period April June,
ˇ
by the 15th day of October for the period July-September, and
ˇ
by the 15th day of January
for the period October to December.
3. The Authority will monitor
the compliance of service providers with mandatory QoS requirements.
The Authority may impose upon
service providers whose QoS indices are deteriorating, mandatory QoS
improvements for failure to meet QoS requirements within the timeframe
stipulated by the Authority.
4. Where the Authority is
satisfied that a service provider has not met its mandatory QoS obligations for
a period of any two (2) quarters within four (4) consecutive quarters, the
Authority may treat such failure as a breach of the service providers license
and may take any enforcement step accordingly.
5. The Authority shall impose
one or more of the following penalties, pursuant to the Telecommunications Law,
on service providers that do not meet the QoS targets set by the Authority:
a. amendment of conditions of
the service providers license or imposition of new terms to ensure compliance
with the Technical QoS and KPI Regulation;
b. suspension of the service
providers license for a limited period or the final cancellation thereof upon
repeated violation, as determined by the Authority;
c.
Imposition of fines
to be evaluated by the Authority in light of the seriousness of the violation
or its recurrence. The Authority shall have the right to impose an additional
fine for each day of delay in eliminating such violation according to article
41 of the Law 431/2002
6. Non-compliance due to
Force Majeure events or external interference affecting radio cells located
within 10 km from the international borders of Lebanon will exempt service
providers from the above mentioned penalties. Nevertheless, QoS mandated
measurements still need to be reported clearly citing the Force Majeure event
and radio cell site.
Where the Authority is
not satisfied with the accuracy or methodology used by a service provider in
its periodic reports, the Authority may, without prejudice to its power to
request information pursuant to the Telecommunications Law, regulations or
license, require the service provider to provide such information, at the
service providers cost, with independently verified information for the
services and period specified by the Authority.
The Authority may publish
on its website and/or in any other form or manner, as it considers appropriate,
the details of the measurements supplied by the service providers pursuant to
this Regulation either on an individual service provider basis or in such
manner that it considers best with a view to carrying out its duties and
obligations under the Telecommunications Law. For the avoidance of doubt such
information provided by the service providers shall not be considered as
confidential information.
Unless otherwise
specifically indicated by context, abbreviations used in this Regulation shall
have the meaning as identified below:
AUC Authentication Centre
BTS Base Transceiver Station
BSC Base Station Controller
BRAS Broadband Access Server
DSLAM Digital
Subscriber Line Access Multiplexer
HLR Home Location Register
MSC Mobile Switching Center
PDH Plesiochronous Digital Hierarchy
RSU Remote Switching Unit
RNC Radio Network Controller
SDH Synchronous Digital Hierarchy
VLR Visitor Location Register
Article 17.
This Regulation will be published and entered into force upon its
publication in the Official Gazette.
Beirut
on the 18th of March 2009
Dr. Kamal
Shehadi
Chairman of the
Telecommunications Regulatory Authority
A.1
Theory for QoS Measurements
1. Like all services,
telecommunications services have a quality component and a price
component. In theory, the price component
should relate closely to the quality component.
But in telecommunications markets this may not always be true.
Telecommunications markets are imperfect, and as a result service providers
can, in some cases, increase profits by lowering QoS, hence uncoupling the
price component from the quality component.
2. The prospect of increasing
profit by lowering QoS increases when the service provider is a monopolist or
is dominant so that its service levels are not subject to effective competitive
pressure from other service providers.
Regulators attempt to counteract this problem by, among other things,
mandating QoS targets and promoting competition.
3. Designing a service
quality monitoring system and analyzing the results is key to an effective QoS
regime. Issues that need to be
considered include factors such as:
a. the relationship of
quality of service to its costs and its value to the consumer;
b. the identification of
areas to be covered;
c. the identification of
information sources;
d. the establishment of a balance
between outcomes (i.e. QoS parameters), outputs (i.e. QoS measurements) and
inputs (measured QoS performance submitted by service providers);
e. the establishment of
criteria for reliability, verifiability and comparability of the available
information;
f. an assessment of the costs
of providing and processing the information; and
g. the identification of
performance indicators that are to be made available for public disclosure.
A.2 Grade of Service
1. A service provider must
decide what services should be delivered to the user and the level of service
quality that the user should experience. This is true for any
telecommunications network independent of the transmission technology applied,
whether it is circuit- or packet-switched, wired or wireless, or optical or
copper-based. Further choices to be made may include the type and layout of the
network infrastructure to support the services, and the choice of techniques to
be used for managing the information transport. These choices may differ
between service providers depending on whether the service provider concerned
is already present in the market, or is starting service in a green field
situation (i.e. a situation where there is no legacy network in place to
consider).
2. QoS is defined in ITU-T
Recommendation E.800 as the collective effect of service performance, which
determines the degree of satisfaction of a user of the service. QoS consists
of a set of parameters that pertain to the traffic performance of the network,
but in addition to this, it also includes other parameters defined in the
recommendation, such as:
ˇ
service support performance;
ˇ
service operability performance;
ˇ
serviceability performance; and
ˇ
service security performance.
3. Grade of Service (GoS) is
defined in ITU-T Recommendation E.600 as a number of traffic engineering
variables to provide a measure of adequacy of a group of resources under
specified conditions. These GoS variables may include probability of loss and
dial tone delay among others. In the recommendation, the values assigned for
GoS parameter variables are termed GoS standards and the values of GoS
parameters achieved under actual conditions are termed GoS results.
4. The key challenge in the
determination of GoS standards involves the apportioning of individual values
to each network element in such a way that the target end-to-end QoS is
obtained.
5. Due to difficulties in
establishing GoS and QoS parameters, Service Level Agreements (SLA) have been
adopted. An SLA is a contract between a customer and a service provider, or between
two service providers. It defines the parameters in question in such a way that
they are understood in the same manner by the customer and the service
provider. Furthermore, an SLA provides for penalties and remedies in cases
where certain terms of the contract are violated. Some service providers have
chosen to issue an SLA governing all customer relationships while others have
adopted SLAs only in their dealings with larger customers. Regulations
regarding SLAs and terms of service will be published as part of the Consumer
Affairs Regulation.
A.3 Overall performance
1. As mentioned above,
network performance concerns the ability of a network or network portion to
provide the functions related to communications between users. In order to
establish how a certain network performs, it is necessary to perform
measurements covering performance parameters (i.e. traffic, dependability,
transmission and charging).
2. Network performance
parameters in the context of GoS pertain only to factors related to traffic performance.
In the context of QoS, network performance also includes the following
concepts:
a. dependability;
b. transmission
performance; and
c. charging and billing
accuracy.
A.4 Reference Configurations
1. In order to obtain an
overview of the network under consideration, it is often useful to produce a
reference configuration. This consists of one or more simplified drawing(s) of
the path a call or a connection can take in the network including appropriate reference
points, where the interfaces between entities are defined. In some cases the
reference points define an interface between two operators, and it is therefore
important to watch carefully what happens at this point. From a GoS perspective
the importance of the reference configuration is the partitioning of the GoS as
described below. Consider a telephone network with terminals, subscriber
switches and transit switches. In this example we ignore the signaling network
and we suppose the call can be routed in one of three ways:
a.
Terminal ŕ subscriber switch ŕ terminal
b.
Terminal ŕ subscriber switch ŕ transit switch ŕ subscriber switch ŕ terminal
c.
Terminal ŕ subscriber switch ŕ transit switch ŕ transit switch ŕ subscriber switch ŕ terminal
2. Based on a given set of
QoS requirements, a set of GoS parameters are selected and defined on an
end-to-end basis within the network boundary for each major service category
provided by a network. The selected GoS parameters are specified in such a way
that the GoS can be derived at well defined reference points (i.e. traffic
significant points). This is to allow the partitioning of end-to-end GoS
objectives to obtain the GoS objectives for each network stage or component, on
the basis of some well-defined reference connections.
3. As defined in ITU-T
Recommendation E.600, for traffic engineering purposes a connection is an
association of resources providing means for communication between two or more
devices in, or attached to, a telecommunication network. There can be different
types of connections as the number and types of resources in a connection may
vary. Therefore, the concept of a reference connection is used to identify
representative cases of the different types of connections without involving
the specifics of their actual realizations by different physical means.
4. Typically, different
network segments are involved in the path of a connection. For example, a
connection may be local, national, or international. The purpose of reference
connections is to clarify and specify traffic performance issues at various
interfaces between different network domains. Each domain may consist of one or
more service provider networks. ITU-T Recommendations I.380/Y.1540 defines
performance parameters for IP packet transfer; its companion ITU-T Draft
Recommendation Y.1541 specifies the corresponding allocations and performance
objectives. ITU-T Recommendation E.651 specifies reference connections for
IP-access networks. Other reference connections may be specified.
5. From the QoS objectives, a
set of end-to-end GoS parameters and their objectives for different reference
connections are derived. For example, end-to-end connection blocking
probability and end-to-end packet transfer delay may be relevant GoS
parameters. The GoS objectives should be specified with reference to traffic
load conditions, such as under normal and high load conditions. The end-to-end
GoS objectives are then apportioned to individual resource components of the
reference connections for dimensioning purposes. In an operational network, to
ensure that the GoS objectives have been met, performance measurements and
performance monitoring are required.
6. In IP-based networks,
performance allocation is usually done on a cloud (i.e. the set of routers and
links under a single or collaborative jurisdictional responsibility, such as an
ISP). A cloud is connected to another cloud by a link (i.e. a gateway router in
one cloud is connected via a link to a gateway router in another cloud).
End-to-end communication between hosts is conducted on a path consisting of a
sequence of clouds and interconnecting links. Such a sequence is referred to as
a hypothetical reference path for performance allocation purposes.
A.5 Fixed Telephony QoS
1. In the field of telephony engineering,
the term QoS comprises all the aspects of a connection, such as time to provide
service, voice quality, echo, loss, reliability and so on. A subset of
telephony QoS is GoS, which comprises aspects of a connection relating to the
capacity of a network. In circuit-switched networks, GoS is the probability of
one party not being able to initiate a call to another party (i.e., a call
attempt blocked and lost owing to congestion).
2. When looking at
circuit-switched networks, QoS is affected by various factors, which can be
divided into "human" and "technical" factors. Human factors
include stability of service, availability of service, delays, and user
information. Technical factors include reliability, scalability, effectiveness,
maintainability, and GoS. In circuit-switched networks, the GoS expresses the
call blocking experienced due to congestion that can result in calls being
lost. It is the responsibility of the service provider to monitor and manage
the GoS of all its services to ensure that the GoS is maintained for every
origin and destination pair.
A.6 Mobile Telephony QoS
1. Many factors affect the
QoS of a mobile network. It is appropriate to look at QoS mainly from the
customer's point of view, that is, QoS as judged by the user. There are standard
metrics of user QoS that can be measured. These metrics are coverage,
accessibility (including GoS), and audio quality. For coverage, the strength of
the signal is measured using test equipment to estimate the size of the cell.
Accessibility is about determining the ability of the network to handle
successful calls from mobile-to-fixed networks and from mobile-to-mobile
networks. Audio quality involves the monitoring of successful calls for a
period of time for clarity of the communication channel. These indicators are
used by the telecommunications industry to rate the QoS of a network.
2. QoS is also measured from
the perspective of an expert (e.g., a teletraffic engineer). Such a measurement
involves assessing the network to see if it delivers the quality that the
network planner has been required to deliver. Certain tools and methods (e.g.,
protocol analyzers, drive tests, and Operation and Maintenance measurements)
are used in such a measurement.
a. Protocol analyzers are connected to Base Transceiver Stations (BTS), Base Station Controllers (BSC), and Mobile Switching Centers (MSC) for a
period of time to check for problems in the cellular network. When a problem is
discovered the staff can record it and it can be analyzed.
b. Drive tests allow the mobile network to be tested through the use of a
team of people who take the role of users and take the QoS measures discussed
above to rate the QoS of the network. This test does not apply to the entire
network, so it is always a statistical sample.
c. In Operation and Maintenance Centers (OMCs), counters are used in the
system for various events which provide the network operator with information
on the state and quality of the network.
d. Finally, customer complaints are a vital source of feedback on QoS, and
must not be ignored by service providers. They must be reported as part of QoS
and Consumer Affairs reporting requirements.
3. In general, GoS is
measured by looking at traffic carried and traffic offered, and by calculating
the traffic blocked and lost. The proportion of lost calls is the measure of
GoS. The GoS standard is thus the acceptable level of traffic that the network
can lose. GoS is calculated from the Erlang-B Formula, as a function of the
number of channels required for the offered traffic intensity.
4. The audio quality of a
cellular network depends on, among other factors, the modulation scheme (e.g.,
Frequency Shift Keying (FSK), Quadrature Phased Shift Keying (QPSK)) in use,
matching channel characteristics, and the processing of the received signal at
the receiver using Digital Signal Processing (DSP).
A.7 Packet-switched Network QoS
1. In the field of
packet-switched network and computer network engineering, the term QoS refers
to control mechanisms that can assign different priorities to different users
or data flows, or guarantee a certain level of performance to a data flow in
accordance with requests from an application program. QoS guarantees are
important if network capacity is limited, especially for real-time streaming
multimedia applications such as Voice Over Internet Protocol (VoIP) and
Internet Protocol Television (IP-TV), since these often require a fixed bit
rate and are delay sensitive.
2. A network or protocol that
supports QoS may agree on a traffic contract with the application software and
reserve capacity in the network nodes during a session establishment phase.
During the session it may monitor the achieved level of performance, for
example the data rate and delay, and dynamically control scheduling priorities
in the network nodes. It may release the reserved capacity during a tear down
phase.
3. The term QoS is also
sometimes referred to as a quality measure as opposed to as a control
mechanism. In computer networking, a good QoS may mean the use of advanced QoS
mechanisms or a high probability that the network is able to provide the
requested level of performance. High QoS is often confused with a high level of
performance, for example high bit rate, low latency and low bit error
probability.
4. Another widespread
definition used especially in VoIP and streaming video is "user perceived
performance" or "degree of satisfaction of the user". In this
context, QoS is the cumulative effect on user satisfaction of all imperfections
affecting the service. This definition includes a human error in the assessment
and demands an appropriate subjective weighting of diverse defects such as
response time, interrupts, noise, cross-talk, loudness levels, frequency
response, noticeable echoes, etc., as well as GoS. This definition resembles
the Mean Opinion Score (MOS) value, which is a subjective quality measure that
can be predicted based on objective performance measures.
5. When the Internet was
first deployed many years ago, it lacked the ability to provide QoS guarantees
due to limits in router computing power. It therefore ran at default QoS level,
or "best effort". There were four "Type of Service" bits
and three "Precedence" bits provided in each message, but they were
ignored. These bits were later re-defined as Differentiated Services Code
Points (DSCP) and are largely honored in peered links on the modern Internet.
6. Many things can happen to
packets as they travel from origin to destination, resulting in the following
problems as seen from the point of view of the sender and receiver
a.
Dropped packets
Routers
might fail to deliver (drop) some packets if they arrive when their
buffers are already full. Some, none, or all of the packets might be dropped,
depending on the state of the network, and it is impossible to determine what
will happen in advance. The receiving application may ask for this information
to be retransmitted, possibly causing severe delays in the overall
transmission.
b.
Delay
It
might take a long time for a packet to reach its destination because it gets
held up in long queues, or takes a less direct route to avoid congestion.
Alternatively, it might follow a fast, direct route. Thus delay is very
unpredictable.
c.
Jitter
Packets
from the source will reach the destination with different delays. This
variation in delay is known as jitter and can seriously affect the quality of
streaming audio and/or video.
d.
Out-of-order delivery
When
a collection of related packets is routed through the Internet, different
packets may take different routes, each resulting in a different delay. The
result is that the packets arrive in a different order than they were sent.
This problem requires special additional protocols to rearrange out-of-order
packets to an isochronous state once they reach their destination. This is
especially important for video and VoIP streams where quality is dramatically
affected by both latency and lack of isochronicity.
e.
Error
Sometimes
packets are misdirected, combined together, or corrupted while en route.
The receiver has to detect this and, just as if the packet was dropped, ask the
sender to resend it.
7. The problems encountered
in a connection-less packet-switched network like the Internet can include
insufficient throughput, packet loss, latency and jitter, which may cause
different problems for different services. Insufficient throughput, latency and
jitter cause problems for real time video; latency and jitter are problematic
in relation to VoIP services; and packet loss may constitute a problem in
connection with the transmission of data files. There are two basic solutions
to these problems. One is to have sufficient or too much (i.e.
over-provisioning) capacity in the network and the other one is to prioritize
communications so that, for instance, real time communications are given
priority over less time-dependent services. Such prioritization is presently
implemented along two different levels of quality, integrated services
(IntServ) and differentiated services (DiffServ). IntServ allows finer grained
prioritization than DiffServ. IPv6 also includes functionalities allowing for
the prioritization of different kinds of communication.
8. It is important to note
that in this context, QoS mechanisms are simply prioritization or rationing
schemes for available capacity. QoS mechanisms do not create any additional
capacity. Queuing theory shows that for
a fixed network load, the sum total of disservices (delay, jitter, and loss) is
a constant. QoS mechanisms allow some of this disservice to be shifted from one
group of users to another.
9. A defined QoS may be
required for certain types of network traffic, for example:
a. streaming multimedia
requires guaranteed throughput;
b. VoIP requires strict
limits on jitter and delay;
c. video
teleconferencing requires low jitter;
d. dedicated link
emulation requires both guaranteed throughput and limits on maximum delay and
jitter; and
e. safety-critical
applications, such as remote surgery and alarm signaling, may require a
guaranteed level of availability (or hard QoS).
These types of network traffic or services are called inelastic,
meaning that they require a certain level of bandwidth to function - any more
than required is unused, and any less will render the service non-functioning.
By contrast, elastic applications can take advantage of however
much or little bandwidth is available. For example, a remote system
administrator may want to prioritize variable, and usually small, amounts of
Secure Shell (SSH) traffic to ensure a responsive session even over a
heavily-laden link.
Definitions and Calculation Methodologies for
Major Parameters
1.
Availability of Telephone Exchange Equipment -
Telephone exchange equipment is unavailable when
there are exchange faults such as those related to switching or transmission.
Availability calculation is based on inputs obtained from all local switches
only. Outage time includes software and hardware faults.
Per local switch minutes =
No. of days in the month x 24 hours x 60 minutes
Per local switch outage minutes = Cumulative duration of outage
per local switch in the month
2. Call Set Up
Time - The call set up time is the period
starting when the address information required for setting up a call is
received by the network and finishing when the called party busy tone or
ringing tone, or answer signal is signaled by the access network to the
terminal.
The
call set-up time will be calculated for all successful call attempts in the
network during the network busy hour on the busiest day of each week during the
reporting period. The average of the weekly call set-up times in the reporting
period is then calculated. This value must be less than or equal to the
specified call set-up time target. A successful call attempt refers to a call
from a calling party who is successfully switched through to the called party,
or receives busy tone when the called party is engaged speaking.
3. Fixed Unsuccessful Call Ratio - An unsuccessful call is defined as a call attempt where the caller does not
hear either a standard busy or a ringing tone.
4.
Fault Rate per Access Line -
Access lines are the distribution circuits from the exchange to the
distribution point, including the fiber, copper, access multiplexers and any
other access equipment where applicable.
5.
Response Time for Operator Services - The duration from the instant when the
address information required for setting up a call is received by the network
(e.g., recognized on the calling user's access line) to the instant the human
operator answers the calling user to provide the service requested. Interaction time with automatic systems
should be excluded. The services covered are the services for operator
controlled and assisted calls that are accessed with special access codes.
Access to emergency services is excluded.
6.
Domestic / International Leased Lines Service
Availability - the measure of the degree to which
the access network is operable and is not in a state of failure or outage at
any point in time. It measures the total downtime of the network, including the
ATM switches, multiplexers, routers, e-mail facilities (if provided) and
connection to the Internet backbone over a month. All scheduled downtime for
the purposes of maintenance and upgrading of the network system will be
excluded from the calculation. However, all service providers must keep their
users informed of such maintenance times. Please note that reported downtime
should include any downtime caused by upstream service providers.
Operational minutes = No. of days in
the month x 24 hours x 60 minutes
Minutes of service downtime =
Cumulative duration of outage per circuit in the month
7.
Mobile Unsuccessful Call Ratio - Unsuccessful
call ratio is defined as the ratio of unsuccessful calls to the total number of
call attempts in the collection period. An unsuccessful call is a call attempt
to a valid number, while in a coverage area, where neither the call is answered
nor called party busy tone, nor ringing tone, nor turned off, is recognized at
the access of the calling user within 40 seconds from the instant when the
subscriber number is received by the network.
The formula includes the attempts to
seize a TCH for an originated or terminated call and the success at assigning a
TCH for an originated or terminated call.
8. Dropped Call
Ratio
9. Congestion
Factor measures the
ratio of congested radio cells (BTS) to the total radio cells (BTS) at the
networks busiest hour of the month.
A cell is
deemed congested at the busiest hour of the month if the carried traffic is
greater or equal than the permissible traffic calculated with the Erlangs B
table for a 2% blocking factor probability.
10. Packet Loss -
Echo requests for a server at an international
exchange in the USA must be less than or equal to the ratio of packet loss.
11. Delay - Providers
are required to send a PING packet from a reference server on the customer side
of a network access node to (a) a server at a point of traffic exchange with
another service provider in Lebanon and (b) a router at an International
exchange in the USA. For the avoidance of doubt, PING packets are Internet
Control Message Protocol (ICMP) echo requests, which are 32 bytes in size for
MS DOS and 56 data bytes for UNIX/MAC. PINGs will be sent at not less than
sixty second intervals, to each of the case (a) and case (b) servers, during
the three busiest hours of the week for each week in the reporting period. The
average round trip delay for all these ping packets and their respective echoes
are calculated separately for case (a) and case (b). The value for case (a)
must be equal to or less than the target for national delay, and the value for
case (b) less than the target value for international delay.
12. Jitter - The
standard deviation of the received times of these same ICMP echo requests at a
server at an international exchange in the USA must be less than or equal to
the JITTER target.
13. ADSL
Throughput - throughput should be reported for all
available speeds
Throughput will be determined from the
download and upload timings of a File Transfer Protocol (FTP) file to and from
a reference server, placed at a point of traffic exchange, in Lebanon, between
service providers. The throughput for each file is calculated for the
downstream test as:
(5
x 8 x 106)/(Time the first byte of file data is received-Time the
last byte of file data
is received)
And for the upstream test as:
(1
x 8 x 106)/(Time the first byte of file data is received-Time the
last byte of file data
is received)
Downstream test
10 test files, each 5Mbytes in size, will be
downloaded from the reference server to a download host on the user side of
each and every access network node during the busiest hour of the busiest day
of the week of the respective access node. The throughput for all such downloaded
files for all access nodes during the reporting period should be arranged in
ascending order and the 90th-percentile reading must be taken. This value must
be greater than or equal to the target value for downstream throughput.
Upstream test
10 test files, each 1Mbyte in size, will be
uploaded to the reference server, from an upload host on the user side of each
and every access network node during the busiest hour of the busiest day of the
week of each access node. The throughput
for all such uploaded files for all access nodes during the reporting period
should be arranged in ascending order and the 90th-percentile reading must be
taken. This value must be greater than or equal to the target value for
upstream throughput.
Network
Outage Report |
||
CONTACT
INFORMATION |
||
Name of
Reporting Entity (e.g., company) |
SP
License No. |
|
Primary
Contact Person: |
E-mail:
|
|
Phone
No. |
||
OUTAGE INFORMATION |
||
Type of
outage □ Emergency Services
outage □ Critical □ Major □ Minor Date of
Incident (dd/mm/yyyy): ---------------------------------------------- Local
Time Outage Began (24-hr hh:mm): --------------------------------- Outage
Duration: ----- hrs
----- min Outage
status when filing this report:
------------------------------------------ Local
Time Outage Resolved (24-hr hh:mm): --------------------------------- |
||
Effects
of the Outage Network
Element(s) Affected --------------- Percentage
of Traffic Affected
--------------- Geographic
Area Affected
Cities: -------------------------------------------
Affected Sites:
------------------------------------------- |
||
Description
of the Outage: ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
||
Explanation
of Outage Duration ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
||
Cause: ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
||
Actions: ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
||
DECLARATION |
||
I am authorized by the Service
Provider to legally bind the provider to the truth, completeness, and
accuracy of the information contained in this report. I on oath depose and
state that the information contained therein is true, correct, and accurate
to the best of my knowledge and belief, and that the Service Provider on oath
deposes and states that this information is true, complete, and accurate. Name: Signature: |
||
Table of Contents
CHAPTER 1. Purpose and Scope of the
Regulation
Article 4. Purpose of the
Regulation
Article 5. Scope of the
Regulation
CHAPTER 3. Rights and Obligations
Regarding QoS and KPIs
Article 8. General
Obligations
Article 10. Target Levels for
QoS and Network Performance Parameters
Article 11. Outage Reporting
and Reparation Requirements
Article 12. Outage reparation
and reporting
CHAPTER 4. Compliance and Penalties
Article 13. General Compliance
Provisions
Article 16. Abbreviationsmeanings
Appendix
A Technical Quality of Service
Appendix
B Set of Quality of Service
Parameters
Appendix
C Network Outage Report