Quality of Experience (QoE) and community networks: collective awareness and action

What is a community network?

Community network (CN), is a term broadly used to indicate the use of networking technologies by, and for, a local community. Free-nets and civic networks may indicate a similar range of projects and services, whereas community technology centers and telecentres generally indicate a physical facility to compensate for lack of access to information and communication technologies (ICT). The area identified with a community network could be a town, city, county, metropolitan neighborhood, state, and occasionally a region.

What do community networks provide?

The most extensive array of services in a community network includes communication services such as web access, instant messaging, IP telephony, IP Television; lots of information services such as news from professional and amateur reporters, news and information from businesses and organizations; community events listings; weather forecasts; listings of governmental offices, businesses and organizations; file repositories and galleries of images of the place. Services include requesting alerts and RSS feeds; searching for goods and services; boards for posting personal and commercial advertisements, local periodic publications.

What is the goal of community networks?

The primary goals of a community network may include providing a sustainable, trusted platform for an urban neighborhood, suburban village or exurban town or region to enhance a vital community and functioning democracy; closing of the digital divide across socio-economic lines; offering easier access to already existing information and services; promotion of local economic development and employment; strengthening the local identity; and/or revitalization, promotion, and/or maintenance of local communal ties.

What is quality of experience?

Quality of experience (QoE), sometimes also known as quality of user experience, is a subjective measure of a customer’s experiences with a service (web browsing, phone call, TV broadcast, call to a Call Center). Quality of Experience systems try to measure metrics that a customer will directly perceive as a quality parameter. Different from the technical QoS parameter, QoE refers to parameters from the subjective users’ perspective. Because quality of experience is something that is created in our mind, we shall not bluntly equate it with any parameters used to describe the “quantity” of experience. One point is that measures of user experience or QoE could be associated with user performance based on actual usage. Since community networks mostly rely on voluntarism, QoE plays an important role to maintain the voluntarism and attracting participants.

QoE measuring techniques and parameters

Quality of Experience (QoE) refers to the overall acceptability of an application or service, as perceived subjectively by the end-user. QoE thereby includes the complete end-to-end system effects (client, terminal, network, services infrastructure, etc.), where overall acceptability may be influenced by user expectations and context. This definition explicitly refers to QoE as a subjective measure and properly measuring QoE should therefore involve tests with actual users, which is a time-consuming and costly process. For service and network providers it is preferable to have tools that objectively reflect within reasonable accuracy the subjective mean opinion score of users. We can classify the parameters that affect QoE into two groups:

  1. Quality of Service (QoS), which refers to the network performance.
  2. Human perception aspects that contributed to a good experience.

QoS factors that refer to the network performance

In packet-switched networks, quality of service 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. 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:

  • Low throughput

Due to varying load from other users sharing the same network resources, the bit rate (the maximum throughput) that can be provided to a certain data stream may be too low for real-time multimedia services if all data streams get the same scheduling priority.

  • Dropped packets

The routers might fail to deliver (drop) some packets if their data is corrupted or they arrive when their buffers are already full. The receiving application may ask for this information to be retransmitted, possibly causing severe delays in the overall transmission.

  • Errors

Sometimes packets are corrupted due to bit errors caused by noise and interference, especially in wireless communications and long copper wires. The receiver has to detect this and, just as if the packet was dropped, may ask for this information to be retransmitted.

  • Latency

It might take a long time for each packet to reach its destination, because it gets held up in long queues, or takes a less direct route to avoid congestion. This is different from throughput, as the delay can build up over time, even if the throughput is almost normal. In some cases, excessive latency can render an application such as VoIP or online gaming unusable.

  • Jitter

Packets from the source will reach the destination with different delays. A packet’s delay varies with its position in the queues of the routers along the path between source and destination and this position can vary unpredictably. This variation in delay is known as jitter and can seriously affect the quality of streaming audio and/or video.

  • Out-of-order delivery

When a collection of related packets is routed through a network, 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 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 sequence.

Factors that contribute to a good experience in community network services

Community networks are not based on the model of customers receiving an opaque service in exchange of service fees under a contract for service provision including the specifications of the service (i.e. ranges of different QoS parameters of the service). Instead, participants in the community networks are co-owners of the network. They are active participants of the community and they have a voice and they should feel capable of having an influence to help the progress of the network. Members decide how they get connected to the network and collectively they decide and fund the growth and upgrades of the network (typically following a dialogue to design the best way, and a crowd-funding model). Therefore the degree of satisfaction (or insatisfaction) and the decisions go together and that openness also contribute to the users to accept some minor technical problems (QoS degradation) as the community can collectively react to these limitations and improve the situation based on that feedback.

A network can be powerful enough for basic web browsing, but if a group in the community collectively decides to upgrade the network to support for instance VOIP, the quality of experience perceived by everyone is discussed in the periodic meetings or in internal mailing lists. As a result of this collective awareness (with human or technical sensors) the required upgrades or adjustments are identified, collectively funded and finally installed or applied by local professional or amateur members of the community itself to maximize the global utility of the network and help participants with any problem. It may take more or less time but that is the process by which community networks can evolve to satisfy the needs of its members with a combination of collective awareness mechanisms, technical means and technical QoS mechanisms, collective decisions, knowledge sharing, mutual support and therefore collective action.

References

  1. Hyun-Jong Kim, Dong-Hyeon Lee, Jong-Min Lee1, Kyoung-Hee Lee, Won Lyu2, Seong-Gon Choi, “The QoE Evaluation Method through the QoS-QoE Correlation Model”
  2. Peter Brooks, Bjørn Hestnes, “User Measures of Quality of Experience: Why Being Objective and Quantitative Is Important”
  3. Fernando Kuipers, Robert Kooij, Danny De Vleeschauwer, and Kjell Brunnstrom, “Techniques for Measuring Quality of Experience”

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