 IEEE, the Institute of Electrical and Electronic Engineers worldwide, is one of the largest organizations that represents the interests of the engineering community, especially the electrical and the computing engineers. An interesting point is, where do these people and this community stand amongst other organizations and bodies when it comes to engine specifications? In this module, we shall see how this organization has been able to exercise its influence in getting its technologies permeated and absorbed into the engine documentation and recommendations. First, IEEE is not exactly involved in this activity. It's not directly involved, but it has an indirect influence, and there are very obvious reasons to that. We can take the example of IEEE to be close to the IETF, which has also been instrumental in developing the engine documentation through an indirect manner, although it is important to state here that IETF also has a direct role to play. Coming back to IEEE, the importance of IEEE from the engine perspective is that it has the technologies which have been used for a very long time, which are all IP based. Let's look at the access side, the distribution side, the core side, or from the pure networking perspective, the LAN side, the wireless LAN side, the MAN side. So we can read out these technologies, and you will immediately know that these are some well-known technologies. The first one is the IEEE 802.3 standard, also known as the Ethernet standard. It's a contention-based LAN standard. It has been there for a very long time. If you remember, we had Ethernet at one megabits per second, then we had 10 base T, then we had 100 base T, then we had 1000 base F. It means these technologies have been existing for a fairly long time. Then we have the IEEE 802.11 or the Wi-Fi standard, also called the wireless fidelity standard. 802.11 starting from its first version 802.11 B, then A, then NG, then C, all these standards have been existing and have such a wide deployment that it is not easy to think about introducing NGN and not mentioning these. And at the MAN or the metropolitan area side, we have the YMAX, that is, it is also known as the WLAN on steroids. IEEE 802.16 is the YMAX, which is a metropolitan area technology. It has the base station and the subscriber stations that can be separated by kilometers. It is again a well-established technology, which works mostly in fixed deployments. Now you see, in the presence of such vast technology base and the existence of this IEEE standard for such a long time. The NGN community had to rely heavily on the existence of these technologies. If we look at the IEEE technologies, let's have an overview. Both the Ethernet and Wi-Fi are predominantly Layer 1 and Layer 2 technologies. That is, these are the standards which are based on the physical layer and the data link layer. The data link layer includes two sublayers, the medium access control sublayer and the logical link control sublayer. Since these two are the Layer 1 and Layer 2 technologies, we are talking about layers from bottom up manner. These two technologies are integrated and very naturally fit with the Layer 3 technology of IP. It means both these technologies are placed right below IP. Any other technology, any standard, any application or any service that can be encapsulated in an IP packet can very easily be transported using these two technologies. Now these technologies are mostly contention based. It means there is no resource reservation a priori. So a natural downside of it is that the quality of service is not guaranteed. So when the ITU-based NGN started considering incorporating these technologies into the NGN recommendations, then they also started giving a serious consideration to how the quality of service can be best provisioned on these two contention-based technologies.