Blocking CoThe aim of this toolbox is to compute blocking probabilities in WDM networks. This work was based on [1], [2], [3], [4] and user is referred to those papers for deeper study.
Because WDM networks are circuit Switched loss networks blocking may occur because of lack of resources.Computation in WDM Networks Toolbox
This is a simulator written in Tcl to simulate a network node carrying GSM and GPRS traffics with QoS mechanisms. The payload type including circuit-Switched voice, VoIP and web traffic, and the performance including packet drop, delay can be analyzed. The implemented QoS mechanism is DiffServ, with 4 RED queues for different services with different priorities.
In recent years, cellular voice networks have transformed into powerful packet-Switched
access networks for both voice communication and Internet access. Evolving Universal
Mobile Telecommunication System (UMTS) networks and first Long Term Evolution
(LTE) installations now deliver bandwidths of several megabits per second to individual
users, and mobile access to the Internet from handheld devices and notebooks is no
longer perceived as slower than a Digital Subscriber Line (DSL) or cable connection.
Bandwidth and capacity demands, however, keep rising because of the increasing number
of people using the networks and because of bandwidth-intensive applications such as
video streaming. Thus, network manufacturers and network operators need to find ways
to continuously increase the capacity and performance of their cellular networks while
reducing the cost.
A decade ago, I first wrote that people moved, and networks needed to adapt to the
reality that people worked on the go. Of course, in those days, wireless LANs came
with a trade-off. Yes, you could use them while moving, but you had to trade a great
deal of throughput to get the mobility. Although it was possible to get bits anywhere,
even while in motion, those bits came slower. As one of the network engineers I worked
with put it, “We’ve installed Switched gigabit Ethernet everywhere on campus, so I
don’t understand why you’d want to go back to what is a 25-megabit hub.” He un-
derestimated the allure of working on the go.
The General Packet Radio Service (GPRS) allows an end user to send and
receive data in packet transfer mode within a public land mobile network
(PLMN) without using a permanent connection between the mobile station
(MS) and the external network during data transfer. This way, GPRS opti-
mizes the use of network and radio resources (RRs) since, unlike circuit-
Switched mode, no connection between the MS and the external network is
established when there is no data flow in progress. Thus, this RR optimiza-
tion makes it possible for the operator to offer more attractive fees.
Mobile telephone service (MTS) is a type of service where mobile radio tele-
phones connect people to the public Switched telephone system (PSTN), to
other mobile telephones or to other communication systems (such as to the
Internet).
Soon after Samuel Morse’s telegraphing device led to a deployed electri-
cal telecommunications system in 1843, waiting lines began to form by those
wanting to use the system. At this writing queueing is still a significant factor in
designing and operating communications services, whether they are provided
over the Internet or by other means, such as circuit Switched networks.
It is more than a decade since GSM was first commercially available. After some unexpected delay, it
seems that finally UMTS is here to stay as a 3G system standardised by 3GPP, at least for another ten
years. UMTS will enable multi-service, multi-rate and flexible IP native-based mobile technologies to be
used in wide area scenarios and also pave the way for a smooth transition from circuit Switched voice
networks to mobile packet services.
Mobile and wireless communication systems are a prominent communications
technology of the twenty-first century with profound economic and social impacts
in practically all parts of the world. The current state of wireless communication
systems allows for a much wider scope of applications than what it used to be
originally, that is, to be a mobile extension of the public Switched telephone
network.
