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Technical Quality of Service

And Key Performance

Indicators

Guidelines

July 3th, 2007

Issue: Draft for Consultation

Telecommunications Regulatory Authority Technical Quality of Service & Key Performance Indicators

CONTENTS

1 PURPOSE OF THE GUIDELINES ........................................................................................... 3 1.1 BACKGROUND ................................................................................................................................. 3 1.2 OBJECTIVE OF THE QOS & KPI GUIDELINES .................................................................................. 3 1.3 LEGAL BASIS .................................................................................................................................. 3 1.4 TRA TECHNICAL QOS AND KPI GUIDELINES ................................................................................. 4 1.5 REVIEW PROCESS ............................................................................................................................ 5 1.6 INTERPRETATION ............................................................................................................................ 5 1.7 TRA REGULATORY PRINCIPLES...................................................................................................... 5 1.8 STRUCTURE OF THE TECHNICAL QOS AND KPI GUIDELINES.......................................................... 5

2 DEFINITIONS .............................................................................................................................. 6 3. TECHNICAL QUALITY OF SERVICE ............................................................................................. 9

3.1. THEORY FOR QUALITY OF SERVICE (QOS) MEASUREMENTS ............................................................ 9 3.2. QUALITY OF SERVICE REGULATION .................................................................................................. 9 3.3. GRADE OF SERVICE............................................................................................................................ 9 3.4. OVERALL PERFORMANCE ................................................................................................................. 11 3.5. REFERENCE CONFIGURATIONS ........................................................................................................ 11 3.6. FIXED TELEPHONY QOS .................................................................................................................. 13 3.7. MOBILE TELEPHONY QOS ............................................................................................................... 13 3.8. PACKET SWITCHED NETWORKS QOS ............................................................................................... 14 3.9. QUALITY OF SERVICE AND NETWORK PERFORMANCE .................................................................... 16

LIST OF ABBREVIATIONS .................................................................................................................. 19 APPENDIX A ........................................................................................................................................... 20


1 Purpose of the Guidelines

1.1 Background

1. The Technical Quality of Service (QoS) & Key Performance Indicators (KPIs) form part of the Regulations issued by the Telecommunications Regulatory Authority (TRA) of Lebanon in accordance with the Telecommunications Law (the Law). These Guidelines are designed to serve potential and current market participants in this sector by providing clear and concise explanations concerning all elements of the Technical QoS and KPI.

2. The Government of Lebanon has embarked upon the process of transforming the state controlled monopoly operator to privately control competitive service provider.

3. The Government has established TRA to monitor the sector, respond to service provider abuse and to enforce the Law.

4. The Law gives TRA specifically the responsibility for consumer affairs, related to telecommunications, in order to provide consumers with adequate levels of protection against service provider abuse, information regarding service prices, quality levels for services, available choices and redress.

5. By outlining the rights and obligations of service providers and consumers as it concerns public telecommunications services, the Consumer Guidelines will detail the specific objectives that the TRA is setting for itself, as well as the telecommunications industry.

1.2 Objective of the QoS and KPI Guidelines

6. The objective of the Guidelines is to identify a meaningful set of KPIs for the mobile, fixed, data and ISP services. It will be the objective of the TRA to ensure these KPIs are regularly published to assist users to make informed decisions as to their service provider(s).

7. The objective of the indicator list is to have an agreed set of QoS indicators. They should allow easier external and internal benchmarking.

8. The chosen indicators should be considered to be of a high relevance to the end-user.

9. The Guidelines have been drafted as part of the introduction of competition in the telecommunications sector in Lebanon

10. .The Guidelines aim to encourage good practice by providers and to promote the provision of universal service and high quality service to end-users.

11. The Guidelines aim to assure consumers of quality service, fairness in tariffs, transparency in billing, and the opportunity of redress for service provider malfeasance.

1.3 Legal Basis

1.3.1 The Telecommunications Law

12. The main legal basis setting the duties and responsibilities for the TRA is the Law, especially Article 5.


13. Articles 25, 26 of the Law address specific responsibilities given to the TRA in matters that are related to Technical QoS and Key Performance Indicators of telecommunications services.

14. Article 5.1, of the Law, outlines the duties and powers of the Authori ty, which includes in its various, articles the authority to issue guidelines for the protection of consumers.

15. Article 5.3 of the Law states that “the Authority shall commit to the principle of developing the services regulations of the Telecommunications Sector according to the most modern technical means and regulatory requirements”. For this purpose, the Authority is empowered to establish rules for collecting and considering the comments and suggestions from sector stakeholders when necessary.

16. Article 31 of the Law delegates to TRA the authority to manage the numbering plan in a non-discriminatory manner.

17. The Law in Article 25 (2) – “Provisions applicable to Public Telecommunications Services Providers” directs the TRA to ensure that

• The Public Telecommunications Services Licence includes mandatory and optional infrastructure targets that are related to the scope of expansion1, and imposes standards that ensure high quality of service.

• The quality of service standards include, but are not limited to requirements related the period of the service provision, call completion rates, fault rates, fault repair times, dial tone delays, and dialling errors.

• The procedures for measuring, reporting and monitoring compliance with the infrastructure, the targets of the expansion and quality of service standards are put in place.

• The Licence include explicit conditions to ensure continuity of service upon the expiry of the Licence

1.4 TRA Technical QoS and KPI Guidelines

18. The Technical QoS and KPI Guidelines apply to all Providers and End Users of Telecommunications Services in Lebanon. They do not apply to users of Private Telecommunications Services.

19. TRA may engage in public consultations regarding Technical QoS prior to the implementation of the Technical QoS and KPI Guidelines.

20. These Guidelines become effective upon completion of the approval and promulgation process set forth in the TRA Code of Practice, including a public consultation and the approval of these Guidelines by the TRA Board. TRA may publish these Guidelines in the Official Gazette and/or on the TRA website.

21. TRA is cognisant that full implementation of the Technical QoS and KPI Guidelines will necessitate existing Providers of Telecommunication Service to undertake a number of changes to internal systems and processes. As a result, TRA will consult with the affected parties and to reach agreement with all parties on individual or generally applicable schedules for compliance with these Guidelines within twelve (12) months from publication, the effective date of the Guidelines. However, unless and until some interim implementation arrangement has been granted to a particular Provider or group of Providers, the present Guidelines will apply in full as of the date of the effective date.

1 Scope related to either number of services or coverage.


22. The Telecommunications Technology Unit (TTU) within the TRA has the responsibility to:

• Determine parameters for performance (Quality and Network).

• Monitor the quality of services offered by service providers designated as SMPs;

• Assists ICAU and the Legal and Licensing unit (LLU) with the establishment of quality of service measures and standards and with annual reviews and other periodic reports provided by licensees.

1.5 Review Process

23. The Technical QoS and KPI Guidelines will be subject to periodic review and may be amended following consultation with interested parties in the light of their experience in the telecommunications sector, as well as ongoing developments in telecommunications markets, and of any changes to Lebanese national law.

1.6 Interpretation

24. Individual clauses and/or guidelines containing the word ‘shall’ are mandatory requirements and are binding on licensed Providers of Telecommunications Services.

25. Individual guidelines containing the word ‘should’ are recommendations to Providers but are not mandatory in and of themselves.

26. Individual guidelines containing the word ‘may’ are permissions to Providers.

27. Individual guidelines containing the word “will” are obligations that the TRA are setting for its own actions.

1.7 TRA Regulatory Principles

28. The TRA outlines the principles pertaining to Technical QoS and KPI in “Developing a Competitive Environment: TRA Regulatory Principles”

29. Specifically, TRA will ensure that all Licensees shall take measure to ensure: a) Billing accuracy; b) Itemised and per service billing; c) Procedures are in place for resolution of customer disputes.

30. TRA will ensure that all Licensees include requirements applicable to the Services provided by providers with designated SMP status concerning: a) Affordability of services; b) Quality of services; c) Network Performance;

1.8 Structure of the Technical QoS and KPI Guidelines

31. The Guidelines are structured as follows and comprise the following items:

Section 2 - Definitions Section 3 – Technical Quality of Service


2 Definitions

32. In the event of conflict or ambiguity between the terms defined herein and the terms defined in the Licence or in the Law then the following order of precedence shall apply:

a) Telecommunications Law

b) The Consumer Affairs Guidelines

c) Service Provider Licence

33. For the purposes of use in these Guidelines, the following terms will have the ascribed meanings:

Authority / TRA means the Telecommunications Regulatory Authority in Lebanon established by virtue of the Telecommunications Law.

Basic Telephony Services are Public Telecommunications Services limited to two-way real-time voice transmission within all of Lebanon offered as a Fixed Telecommunications Service over a Self-operated Network. Basic Telephony Services are classified for licensing purposes as requiring a Public Fixed Network licence.

Consumer means any natural or judicial person other than a Provider of Telecommunications Services. See also End User.

Consumer Affairs means any regulation related to consumers and Telecommunications Equipment and Telecommunications Services.

Customer means the Person who receives Telecommunications Services and pays the corresponding fees for a period of time by virtue of an agreement with or pursuant to terms established by the Service Provider.

Customer Premises Equipment (CPE) means any technical devices, including wiring that are suitable for connecting to the Network Termination Interface that is owned or controlled by an End User within his or her private premises without commercial purpose and which may be used to originate, route, terminate, store or convert any communication over the network. Importation, sale and use of such CPE may be subject to equipment standards specified in the Radio and Telecommunications Terminal Equipment (RTTE) Type Approval Guidelines but is not subject to licensing under the present Guidelines

Emergency Services are services given to the Public free of charge as defined from time to time by the regulator in consultation with the licensed Service Provider(s).

End User (or User) means any natural or judicial person, excluding Providers of Telecommunications Services, purchasing, consuming or using Telecommunications Services solely for their own consumption. Irrespective of whether an End User is an individual, household, or institutions of any kind, such End User may not provide access to Telecommunications Services to persons outside their respective Defined User Group, nor provide access on a commercial scale or for profit. End users are Consumers.

Facility means a physical component of a telecommunications network, other than CPE, including wires, lines, terrestrial and submarine cables, wave guides, optics or other equipment or object connected therewith, used for the purpose of telecommunications and includes any post, pole, tower, standard, bracket, stay, strut, insulator, pipe, conduit, or similar thing used for carrying, suspending, supporting or protecting the structure.

Information means signs, signals, writings, sounds and other data.


Interconnection means the physical and logical linking of telecommunications networks used by one or more Service Provider in order to enable the Users or Subscribers of the same or another provider to communicate, and linking any service to another one across Networks, be it locally or internationally.

International Telecommunications Services means Telecommunications Services provided between Lebanon an abroad.

Network means a system of interconnected facilities designed to carry traffic including any Telecommunications Service. Network here includes both the physical components (Infrastructure) and the various traffic networks, each representing a particular interconnection of infrastructures for certain Telecommunications Services.

Network Performance means the ability of a network portion to provide the functions related to communication between users (ITU-T Rec. E.800). Non-discrimination means supplying the same product/service to different consumers on the same financial, technical and service terms.

Price Cap - A method of setting prices whereby the SMP Provider is given a limit on the average per usage (or per consumer) revenue it may collect, but within that is given flexibility on how to set the prices, and is permitted to recover profits above those cost-of-service regulation would consider reasonable, up to some limit, as an incentive to be more efficient

Private Telecommunications Services means a Restricted Telecommunications Service provided to some Defined User Group or Groups:

• within or between contiguous premises or between premises utilising any means appropriate for transmission and reception within such limited geographic area, or

• Between any number of non-contiguous locations or premises where these are connected by transport or transport segments obtained from another Provider, including on a leased capacity basis. Within these locations or premises, the provisions of the above clause apply.

Service Provider means any individual or legal person providing Telecommunications Services to others on a commercial scale or for profit. The TRA may by Guideline or Decision set forth specific criteria concerning the scale of operations sufficient for a person to be considered operating on a commercial scale.

Public Telecommunications Network means fully interconnected and integrated telecommunications systems consisting of various means of transmission and switching, used to provide Basic Telephone Service and other Public Telecommunications services.

Quality of Service means the collective effect of service performance which determine the degree of satisfaction of a user of the service (ITU-T Rec. E.800). and the statement of the level of quality required by the applications of consumers/users of a service, which may be expressed non-technically (ITU-T Rec. G.1000).

Service Provider with Significant Market Power (SMP) means a Service Provider that has the ability to practically affect the terms of the subscription relevant to the price and supply in a specific market relevant to a telecommunications service due to controlling essential facilities, or using its position in the market. Essential telecommunications facilities means a Public Telecommunications Service or infrastructure that is exclusively or predominantly provided by one or a few number of Providers and cannot feasibly be substituted, economically or technically, in order to provide the service.


Slamming occurs when a consumer’s service is switched from one provider to another without the consumer’s permission.

Subscriber is another term for Customer (See definition above).

Telecommunications Services means the provision of services inclusive of the transmission/reception and routing of information in a potentially interactive manner by any technological means. Telecommunications Services also means the provision of Infrastructure or elements thereof necessary for the provision of such services. Telecommunications Services include specific service categories, including but not limited to Network and End-User Services, Telephony, Value-Added Telecommunications Services, and Telecommunications Services provided to the Public or Restricted groups of persons (Defined User Groups or Licence Areas/Service Territories). The provision of any Telecommunications Service in Lebanon comes under the jurisdiction of the TRA and is subject to a Licence.

Universal Access (UA) describes the availability, within a defined reasonable travel time, of shared access points to Universal Services (such as payphones, telecentres, etc.)

Universal Provision is defined here to include both Universal Service and Universal Access.

Universal Service (US) describes availability of Telecommunications Service at the consumer’s premises, or to him/her personally on a full-time basis.

Value Added Services are services which may or may not be Telecommunications Services and are characterised by:

• Alteration in form, code, protocol, or any other feature of the consumer-transmitted Information at the Network Termination Interface by means of telecommunications.

• Information provision to a User or Consumer, including the re-composition at the Network Termination Interface of Information originally transmitted by a User or Consumer.

• Provision of stored Information for interaction with a User or Consumer, including information stored on or off the network that enables the Consumer to access the network or utilise any services provided over a network.

Value-Added Services used by Consumers but provided entirely by Customer Premises Equipment (CPE) of any kind on the Consumer side of the Network Termination Interface are not subject to Licensing, nor will this type of Value Added Service be considered as relating to or involving a Telecommunications Service.


3. Technical Quality of Service

3.1. Theory for Quality of Service (QoS) Measurements

34. Like other services, telecommunications services have a quality component and a price component. In theory, the price component should closely relate to the quality component. But in telecommunications markets this may not always be true.

Telecommunications markets are regulated, and as a result, telephone operators could, in theory, increase profit by lowering QoS, hence unbundling the price component from the quality component.

35. The prospect of increasing profit by lowering QoS is of most concern when the telephone operator is a monopolist, or is dominant so that its service levels are not subject to effective competitive pressure from other operators. Regulators attempt to counteract this propensity by mandating QoS targets.

36. Designing a service quality monitoring system and analysing the results is key to effective consumer protections. Issues that need to be considered include factors that

a) Relate the quality of service to its costs and its value to the consumer;

b) Identify areas to be covered;

c) Identify information sources;

d) Establish a balance between outcomes, outputs and inputs;

e) Establish criteria for reliability, verifiability, and comparability of the available information;

f) Assess the costs of providing and processing the information; and

g) Identify the performance indicators that are to be made available for public disclosure.

3.2. Quality of Service Regulation

37. There exist two generally accepted methods for a regulator to regulate QoS of a telephone operator:

a) The traditional approach where QoS targets are set against which the telephone operator performance is measured with a system of penalties and rewards based on QoS targets; and

b) The innovative approach where the QoS variable is incorporated in the price cap formula as the Q-factor where lower quality leads to lower consumer prices, while higher quality may lead to higher prices.

3.3. Grade of Service

38. A network operator must decide what services the network should deliver to the end-user and the level of service quality that the user should experience. This is true for any telecommunications network, whether it is circuit- or packet-switched, wired or wireless, optical or copper-based, and it is independent of the transmission technology applied.


Further decisions to be made may include the type and layout of the network infrastructure for supporting the services, and the choice of techniques to be used for handling the information transport.

These further decisions may be different, depending on whether the operator is already present in the market, or is starting service from a green field situation (i.e. a situation where there is no legacy network in place to consider).

39. As for the Quality of Service (QoS) concept, it is defined in the ITU-T Recommendation E.800 as: The collective effect of service performance, which determines the degree of satisfaction of a user of the service. The QoS consists of a set of parameters that pertain to the traffic performance of the network, but in addition to this, the QoS also includes a lot of other concepts. They can be summarized as:

i) Service support performance

ii) Service operability performance

iii) servicibilty performance and

iv) Service security performance

40. The detailed definition of these terms is given in the E.800. The better service quality an operator chooses to offer to the end user, the better is the chance to win customers and to keep current customers. But a better service quality also means that the network will most likely become more expensive to design, install, operate, and maintain and this normally, also has a bearing to the price of the service.

41. When the quality decision is in place the planning of the network proper can start. This includes the decision of a transport network technology and its topology as well as reliability aspects in case one or more network elements become malfunctioning. It is also at this stage where the routing strategy has to be determined.

42. This is the point in time where it is needed to consider the Grade of Service (GoS). It is defined in the 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 grade of service variables may be probability of loss, dial tone delay, etc To this definition the recommendation furthermore supplies the following notes:

(1) The parameter values assigned for grade of service variables are called grade of service standards.

(2) The values of grade of service parameters achieved under actual conditions are called grade of service results

43. The key point to solve in the determination of the GoS standards is to apportion individual values to each network element in such a way that the target end-to-end QoS is obtained.

44. Due to different views taken by GoS and QoS a solution to take care of the problem has been proposed. This solution is called a Service Level Agreement (SLA). This is really a contract between a user/network oeprator and a network operator. In this contract it is defined what the parameters in question really mean. It is supposed to be done in such a way, that it will be understood in the same manner by the customer and the network operator. Furthermore, the SLA defines what is to happen in case the terms of the contract are violated. Some operators have chosen to issue SLA for all customer relationships they have (at least in principle), while others only do it for big customers, who know what the terms in the SLA really means.


3.4. Overall performance

45. As mentioned above the 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 and the measurements have to cover all the aspects of the performance parameters (i.e. trafficability, dependability, transmission and charging).

46. Furthermore, the network performance aspects in the GoS concept pertains only to the factors related to trafficability performance in the QoS terminology. But in the QoS world network performance also includes the following concepts:

a. Dependability b. Transmission performance and c. Charging correctness

It is not enough just to perform the measurements. It is also necessary to have an organization that can do the proper surveillance and can take appropriate action when problems arise. As the network complexity keeps growing so does the number of parameters needed to consider. This means that automated tools will be required in order to make it easier to get an overview of the most important parameters to consider.

3.5. Reference Configurations

47. In order to obtain an overview of the network under consideration, it is often useful to produce a so-called 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. Suppose the call can be routed in one of three ways:

d. Terminal à subscriber switch à terminal

e. Terminal à subscriber switch à transit switch à subscriber switch à

terminal


f. Terminal à subscriber switch à transit switch à transit switch à

subscriber switch à terminal

48. 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.

49. As defined in 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.

50. Typically, different network segments are involved in the path of a connection. For example, a connection may be local, national, or international. The purposes of reference connections are clarifying and specifying traffic performance issues at various interfaces between different network domains. Each domain may consist of one or more service provider networks. Recommendations I.380/Y.1540 defines performance parameters for IP packet transfer; its companion Draft Recommendation Y.1541 specifies the corresponding allocations and performance objectives. Recommendation E.651 specifies reference connections for IP-access networks. Other reference connections are to be specified.

51. 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.


52. 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 Internet Service Provider, 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.

3.6. Fixed Telephony QoS

53. In the fields of telephony, the engineering term Quality of Service (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 Grade of Service (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, that is, a call attempt blocked and lost owing to congestion.

54. 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, user information. Technical factors include: reliability, scalability, effectiveness, maintainability, Grade of Service, etc. In circuit-switched networks, the GoS expresses the blocking experienced owing to congestion and can result in calls being lost. Thus it is the responsibility of the telecommunications 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.

3.7. Mobile Telephony QoS

55. Many factors affect the quality of service of a mobile network. It is correct 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 QoS to the user that can be measured to rate the QoS. These metrics are: the coverage, accessibility (includes GoS), and the audio quality. In coverage the strength of the signal is measured using test equipment and this can be used 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. The audio quality considers monitoring a successful call for a period of time for the clarity of the communication channel. All these indicators are used by the telecommunications industry to rate the quality of service of a network.

56. The QoS in industry is also measured from the perspective of an expert (e.g. teletraffic engineer). This involves assessing the network to see if it delivers the quality that the network planner has been required to deliver. Certain tools and methods (protocol analyzers, drive tests and Operation and Maintenance measurements), are used for this QoS measurement:

a. Protocol analyzers are connected to BTSs, BSCs, and MSCs 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 the 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 the QoS, and must not be ignored.

57. 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. For cellular circuit groups an acceptable GOS is 0.02. This means that two users of the circuit group out of a hundred will encounter a call refusal during the busy hour at the end of the planning period. The grade of service 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.

58. The audio quality of a cellular network depends on, among other factors, the modulation scheme (e.g. FSK, QPSK) in use, matching to the channel characteristics and the processing of the received signal at the receiver using DSP.

3.8. Packet switched Networks QoS

59. In the fields of packet-switched networks and computer networking, the traffic engineering term Quality of Service refers to control mechanisms that can provide different priority to different users or data flows, or guarantee a certain level of performance to a data flow in accordance with requests from the application program. Quality of Service guarantees are important if the network capacity is limited, especially for real-time streaming multimedia applications, for example voice Over IP and IP-TV, since these often require fixed bit rate and may be delay sensitive.

60. A network or protocol that supports Quality of Service 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.

61. The term Quality of Service is sometimes used as a quality measure with many alternative definitions, rather than referring to control mechanisms. In computer networking, a good QoS may mean advanced QoS mechani sms, or 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.

62. Another widespread definition used especially in telephony and streaming videois "user perceived performance" or "degree of satisfaction of the user". In this context, QoS is


the cumulative effect on subscriber satisfaction of all imperfections affecting the service. This definition includes the human 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., and also includes grade of service. This definition resembles the Mean Opinion Score (MOS) value, which is a subjective quality measure that can be predicted based on objective performance measures.

63. When the Internet was first deployed many years ago, it lacked the ability to provide

Quality of Service 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 Diffserv Code Points (DSCP) and are largely honored in peered links on the modern Internet.

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 The 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 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 necessitates special additional protocols responsible for rearranging 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, or 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 repeat it.

64. The problems encountered in a connection-less packet-switched network like Internet can be insufficient throughput, packet loss, latency and jitter (variable delays) 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 voice 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 communication is given priority over less time-dependent services. Such prioritization is, presently, implemented in two different levels of quality, integrated services (IntServ) and differentiated services (DiffServ), where IntServ is a finer grained prioritization while DiffServ is coarser grained. The new IPv6 also includes functionalities allowing for prioritization of different kinds of communication.

65. It is important to note that QoS mechanisms are simply prioritization (or rationing) schemes for the available capacity. QoS mechanisms do not create any additional capacity. The law of work conserving queues, from the field of 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.

66. A defined Quality of Service may be required for certain types of network traffic, for example:

a – streaming multimedia may require guaranteed throughput b - IP telephony or Voice over IP (VOIP) may require strict limits on jitter and delay c - Video Teleconferencing (VTC) requires low jitter d - Alarm signaling (e.g. Burglar alarm) e - Dedicated link emulation requires both guaranteed throughput and imposes limits on maximum delay and jitter f – A safety-critical application, such as remote surgery may require a guaranteed level of availability (this is also called hard QoS).

These types of service 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 SSH traffic to ensure a responsive session even over a heavily-laden link.

3.9. Quality of Service and Network Performance

67. The TRA will publish on an annual basis target levels for a defined set of QoS and network performance parameters. (Appendix A)

68. TRA has identified a set of key QOS indicators that are mandatory on all Service Providers with SMP. TRA will be monitoring the compliance of Service Providers with the mandatory QoS indicators and will request SMP Service Providers to regularly report on these indicators.

69. The remainder of the QoS indicators are being provided to guide SPs and consumers. Consumers will be able to use these indicators to inquire about the quality


of service that they will be purchasing from SPs. It is understood that the list of mandatory indicators may change as the TRA deems necessary to meet market and consumer requirements.

70. The Target set of QoS and network performance parameters may change in scope from year to year and the target parameters may vary in degree from time to time as TRA, after due consultation, based on new telecommunications technology and/or research performed by the Authority or any other recognised national or international technical research institute. The parameters are to include, but shall not necessarily be limited to, the:

i) supply time for connection;

ii) fault rate and fault repair time per access line;

iii) call set up time;

iv) response time for operator services and inquiries;

v) billing accuracy;

vi) unsuccessful call ratio;

vii) Proportion of public telephones out of service.

71. The Table in Appendix A indicates which of the parameters are mandatory for Providers with designated SMP s tatus and those that are recommendations.

72. Targets will be set for each major category of service, which require a Telecommunications Licence as detailed in the TRA Licensing Guidelines.

73. If test of the marketplace indicate that the market for the service is competitive as per the SMP Guidelines, then the QoS targets become recommendat ion.

74. The Service Quality targets that measures the key attributes of service quality based on TRA developed baseline performance indicators may reflect either recent historical performance or reflect standards to improve service quality where current performance is not adequate.

75. During any regulatory period determined by TRA the service provider's performance should be reviewed annually based on monthly reporting and compared to the baseline performance standards for each QoS item. If service quality has deteriorated, the plan must include pre-set penalties of two types: customer-specific credits and a reduction in allowable earnings.

76. TRA may impose upon Telecommunications Service Providers with deteriorating QoS indices mandatory QoS improvements and fines the Telecommunications Service Providers for failure to meet the QoS requirements within the timeframe stipulated by the Authority.

77. Telecommunications Service availability can be affected by disruptions consisting of:


a) An inability to access the network; and

b) An inability to complete communications effectively once the network has been accessed.

78. Providers of Telecommunications Services that provide communications whether terrestrial, wireless or satellite shall be required to provide network outage reports to the TRA whenever an outage:

a) affects an entire RSU, local switch, transit switch, or international switch , or trunk cable, or E1 transmission link for 30 (thirty) minutes; and

b) lasts for more than 60 (sixty) minutes under any and all circumstances;

c) Affects the emergency service for thirty (30) minutes under all circumstances.


List of Abbreviations

BTS Base Transceiver Station

BSC Base Station Controller

CPE Customer Premises Equipment

CPL Consumer Protection Law

GoS Grade of Service

ICAU Information and Consumer Affairs Unit

LLU Legal and Licensing unit

KPI Key Performance Indicators

MSC Mobile Switching Center

QoS Quality of Service

RTTE Radio and Telecommunications Terminal Equipment

SMP Significant Market Power

TRA Telecommunications Regulatory Authority

TTU Telecommunications Technology Unit

UA Universal Access

US Universal Service VPNs Virtual Private Networks


Appendix A Set of Quality of Service Indices

QoS/Network Performance Parameter

Target Level Minimum Level below which

TRA may impose

penalties

Mandatory for SMP

Operators* (early period)

Fixed Network Licence Supply Time for Connection 99% in 3 days NO Fault Rate per Access Line 12 failures per 100 lines

per annum NO

Fault Repair Time 95% within 72 hours NO Call Set Up Time (Post dialling delay to ring tone)

1.9 seconds national at busy hour 3.9 seconds for international at busy hour

YES

Response Time for all Service Provider Services (Time to answer from last digit dialled)

99% within 15 seconds NO

Proportion of Public Pay-Telephones in Working Order

>=96% NO

Billing Accuracy 0.8 complaints per 1000 bills

YES

Unsuccessful Call Ratio (% of call attempts)

0.6% National at busy hour 5% International at busy hour

YES

Dial up internet access Upstream 80% 19.6 Kbit/s Downstream 32 Kbit/s

NO

Complaint handling 95% resolved within 10 working days

NO

Speech Quality Mean Opinion Score MOS >=4.1

NO

Echo Cancellers Usage at the Central Office Ratio of Speech Connections experiencing Echo on each Central Office

99.9% of each Central Office is using Echo Canceller for each Speech connection. <=0.1% of total speech connections at busy hour

YES

YES

Switch Processor Load <=85% at busy hour NO Resolution time of International Gateway fault impacting traffic

Within 1 hour NO

Resolution time of National Transit Switch fault impacting traffic

Within 1 hour NO


QoS/Network Performance Parameter

Target Level Minimum Level below which

TRA may impose

penalties

Mandatory for SMP

Operators* (early period)

Resolution time of Switch fault impacting traffic

Within 4 hours NO

Resolution time of a Backbone Link fault impacting traffic

Within 4 hours NO

Load on Signalling Link 50% for each signalling link at busy hour

NO

Congestion level per Traffic ROUTE

<=1% at busy hour NO

Bill correctness complaints 0.8 complaints per 1000 bills

NO


International Voice Network Licence

Call Set Up Time (Post dialling delay to ring tone)

3.9 seconds for international

YES

Echo Cancellers Usage at the Central Office Ratio of Speech Connections experiencing Echo on each Central Office

99.9% of each International Gateway Switch is using Echo Canceller for each Speech connection. <=0.5% of total speech connections at busy hour

YES

YES


<=5% at busy hour YES


NO


5% International at busy hour

YES


Within 4 hours NO

Resolution time of International Gateway fault impacting traffic

Within 1 hour NO

Switch Processor Load <=85% at busy hour NO

Speech Quality MOS >=3 NO


Leased Lines Domestic

Supply Time for Connection 90% completed on agreed day

NO

Consumer Fault Rate per leased line

8 failures per 100 consumers per quarter

NO

Fault Repair Time 92% within agreed repair time

YES


Leased Lines International

Supply Time for Connection 75% completed on agreed day

NO

Consumer Fault Rate per leased line

10 failures per 100 consumers per quarter

NO


Within 4 hours YES


YES


Mobile Network License

Supply Time for Connection On demand for pre paid and for post paid

YES

Call Set Up Time (Post dialling delay to ring tone)

1.9 seconds national at busy hour 3.9 seconds for international at busy hour

YES

Response Time for all Service Provider Services. (Time to answer from last digit dialled)



YES


0.6% National at busy hour 5% International at busy hour

YES

Successful call completion rate (Mobile initiated)

95% at busy hour for calls within the Service Provider GSM Mobile Network. 95% at busy hour for calls between the Service Provider’s GSM Mobile Network and the GSM Mobile Network of any other Mobile Provider.

NO

Successful call completion rate (Incoming from another network)

95% at Busy Hour NO

National Dropped call rate Less than 1% at busy hour.

YES

Dropped call rate in Greater Beirut Area

Less than 1% at busy hour

YES

Successful network handovers (HO successful + return to old channel)

Greater than 99% at busy hour

NO

Success handovers at Cell level (HO successful + return to old channel)

Greater than or equal to 90% at busy hour

NO

Circuit Switched Data services CDS Packet Switched Data Services PDS Mobile Station Configuration 4+1)

Upstream 80% 14.4 Kbit/s at busy hour Downstream 14.4 Kbit/s at busy hour Upstream 80% 14.4 Kbits/s at busy hour Downstream 80% 38.4 Kbits/s at busy hour

NO


Internal Round Trip Delay RTT <=120 ms Internal

Network <=600 ms End – to - End

NO

Ratio of Base Stations with a Downlink Retransmission Rate <=10%

>=95% at busy hour NO

Ratio of Base Stations with a Uplink Retransmission Rate <=10%

>=95% at busy hour NO

Complaint handling 95% resolved within 5 working days

NO

Dropped calls Per Cell 1 dropped call per 100 calls per Cell at busy hour

YES

2% Blocking Factor at Base Station level per Cell on Traffic channel

95% of all Cells at busy hour

YES

0.5% Blocking Factor at Base Station level per Cell on Signalling channel

95% of all Cells at busy hour

YES


NO

MSC / GMSC / BSC / HLR / AUC / SCP / STP / SGSN / GGSN Processor Load




Resolution Time of BTS fault impacting 30% of Cell traffic

Within 8 hours NO

Resolution time of BSC or Backbone Link fault impacting traffic

Within 4 hours NO

Resolution time of MSC fault impacting traffic

Within 1 hour NO

SMS Mobile Originated Delivered

95% Delivered with 24 hours

YES

SMS mobile Terminated Delivered

90% Delivered within 24 hours

YES

MMS Mobile Originated Delivered


NO

MMS Mobile Terminated Delivered


NO


Data wireless Network Narrow Band (Below E1) License

Supply Time for Connection

90% completed on agreed day YES

Customer Fault Rate per leased line

10 failures per 100 customers per quarter NO

Core Router Processor Load

<=85%

NO

Resolution Time of Fault impacting Core Router

Within 1 hour NO

Resolution time of Backbone Link fault impacting traffic

Within 4 hours NO

Ratio of Packet Loss

<=5% Packet Loss per session YES

End-to-End budget Delay assuming 50 milliseconds Jitter Buffer

<=150 milliseconds (ms)

YES

Fault Repair Time

90% within agreed repair time YES


Data Wireless Network Broadband (>=E1) License Supply Time for Connection

95% completed on agreed day YES

Customer Fault Rate per leased line

5 failures per 100 customers per quarter YES

Core Router Processor Load

<=85%

NO


Within 1 hour NO

Resolution time of Backbone Link fault impacting traffic

Within 4 hours NO

Ratio of Packet Loss

<=5% Packet Loss per session YES


<=150 milliseconds (ms)

YES

Fault Repair Time

95% within agreed repair time YES


Pre Paid Card Services

Service Fulfilment On demand NO Number of Complaints NO

Complaint Handling 95% resolved within 5 working days

NO

Debit Accuracy 99.99 % YES


Audiotext

Service Fulfilment 95% completed on day YES Number of Complaints 5 complaints per 100

consumers per quarter NO


NO


YES

Sound quality MOS >=4.1 NO


Premium Charged services

Service Fulfilment On demand YES Number of Complaints 5 complaints per 100

consumers per quarter NO


NO


YES


Free phone services

Fulfilment NO Bill correctness complaints 0.8 complaints per 1000

bills NO

Complaints NO


ISP

Supply Time for Connection 95% in 14 days NO Core Router Processor Load <=85%

NO


Within 1 hour NO

Fault rate per 100 consumers 10 failures per 100 consumers per month

NO


NO

Dial-Up Call Set Up Time (Post dialling delay to ring tone) ADSL Service

1.9 seconds national Always Connected

YES

Response Time for Support enquiries



YES

Unsuccessful Connect Ratio (Number of call attempts)

10 per 1000 attempts YES

ADSL Throughput 128 Kbits Upstream 80% 32Kbit/s Downstream 80% 128 Kbit/s

YES


YES


NO


NO

ADSL Throughput 2048 Kbit/s Upstream 80% 128Kbit/s Downstream 80% 2048 Kbit/s

NO

SDSL Throughput 128 Kbits Upstream 95% 128Kbit/s Downstream 95% 128 Kbit/s

NO


NO


NO

SDSL Throughput 1024 Kbits Upstream 95% 1024 Kbit/s Downstream 95% 1024 Kbit/s

NO

SDSL Throughput 2048 Kbit/s Upstream 95% 2048 Kbit/s Downstream 95% 2048 Kbit/s

NO


Ratio of Packet Loss <=5% Packet Loss per session YES


150 milliseconds (ms)

YES

- End of Technical Quality of Service & Key Performance Indicators Guidelines -

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