IPTV Monitoring Challenges
Challenges of IPTV Quality Assurance
IPTV Video Quality
Broadcast IPTV is a real-time event with continuously changing content, therefore IPTV quality assurance must be done in real time. However, this approach is reactive.Â The real time (or passive) approach must also be backed up by a proactive regime of full reference (active) video and audio testing. In addition, test traffic injection must be considered at quality sensitive junctures to determine issues in advance of the end user. End to end, network wide IPTV monitoring ensures that subscriber viewing quality is maintained throughout the entire IPTV delivery chain.
End-to-End IPTV Monitoring Solutions
IPTV Content Quality
IPTV content quality degrades with varying packet loss and increased jitter levels, the addition of a new node or delay inducing device in the network will adversely effect the quality of the IPTV broadcast. Monitoring solutions must therefore determine delay and loss metrics as well as qualitative video scoring.
IPTV Bandwidth Efficiency
Efficient bandwidth usage can be linked with the type of codec used in the delivery of IPTV content. Deploying codecs such as MPEG-4 coupled with the utilization of variable bit rate (VBR) stream delivery and attempts to improve channel change rates can provide subscribers with extra capacity. For example, bandwidth efficient methods can ensure more than one IPTV appliance is supported for each residential gateway, perhaps offering a mix of standard and HD TV support. However, bandwidth efficiency is offset by quality challenges, due to increased sensitivity. IPTV monitoring solutions must not simply use jitter and packet loss methods to establish video quality but must also support codec based quality metrics. A codec based quality assessment can deal with the differences in say, MPEG-2, MPEG-4. In addition, an effective IPTV monitoring system must also cope with VBR and CBR stream quality monitoring at different points in the network.
Video Audio Synchronization
Network parameters and system configurations can induce video audio nuisances such as synchronisation issues into the IPTV stream. Television as an integrated visual and audio experience requires quality assurance solutions with integrated performance monitoring for both image and audio quality.
IPTV Channel Change, cause and effect on service quality
IPTV channel change surge events such as the half time™ phenomenon during key sports events combined with support for instant channel change mechanisms can cause unacceptable delays, spoiling viewing experience. Channel change mechanism can also indirectly lead to poor IPTV viewing quality. This can be due to multicast (IGMP/MLD or hybrid multicast/unicast) performance problems and/or middleware at access and aggregation points. Rapidly isolating and resolving service assurance problems can be simplified with a proactive monitoring solution. Strategically placed IPTV probes at various network nodes can isolate problems within seconds of occurring and prevent IPTV subscribers flooding help lines with unnecessary support calls or simply canceling their service.
Integrated IPTV Monitoring Solutions
Service Providers are deploying IPTV solutions that can integrate into existing network management systems and or can operate independent of a centralized resource. This important resiliency feature offers the greatest flexibility in times of network sector outage, or in the case of power failure, the probe continues to monitor and capture quality violations. IPTV monitoring solutions with built in memory enable Providers retrieve stats and captures of the poor quality content at a later date for replay.