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By
Ron de Lange
We all know mobile data traffic is skyrocketing, fueled by the rampant use of smartphones, tablets, and compelling applications such as mobile video and social networking. And there is no slowdown in sight.
Operators know that their 3G networks are not equipped to manage this high level of traffic growth. They’re looking to all-Internet protocol (IP) networks such as long term evolution (LTE) and IP multimedia subsystem (IMS) to provide the bandwidth required to support data-hungry devices and applications and to cost effectively address the growing gap between traffic and revenue growth.
According to the Global mobile Supplier Association’s (GSA) recent report, 180 operators in 70 countries are currently investing in LTE, with at least 64 LTE networks anticipated to be in commercial service by the end of 2012. As LTE networks are deployed over the next few years, operators will be faced with a number of challenges as their networks become more complex, including scalability and cost management. Diameter can help address those challenges.
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3G networks are not equipped to manage this high level of traffic growth. |
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extensive use of Diameter protocol
interfaces for LTE and IMS networks,
but the organization has not defined a
separate Diameter signaling
infrastructure.
Without a separate Diameter signaling
infrastructure at the network core to
facilitate signaling between network
elements, endpoints such as mobility
management entities (MMEs) and home
subscriber servers (HSSs) must utilize
direct signaling connections to each
other, forming a mesh-like network
architecture. Network endpoints must
handle all session-related tasks such
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Why Diameter Signaling?
The majority of operators around the globe still connect their networks through the exchange of well-defined SS7 messages. As networks evolve, SS7 signaling is being replaced by Diameter and SIP-based equivalents. While LTE defines Diameter-based rather than SS7 interfaces, the majority of SS7 functionalities still have to be performed in LTE networks.
The Diameter protocol, using stream control transmission protocol (SCTP) for transport, is used widely in the all-IP, service-oriented IMS and LTE architectures. Within the IMS control and service planes, Diameter plays a central role in policy, charging, authentication, and mobility management.
Diameter Routing Challenges
The Third Generation Partnership
Project (3GPP) has specified the
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as routing, traffic management,
redundancy, and service
implementation. Initially, implementing
an IMS or LTE network without a
signaling core may be sufficient, but as
traffic levels grow, the lack of a capable
signaling infrastructure poses a
number of significant challenges,
including:
- Scalability: Each endpoint must maintain a separate SCTP association with
each of its Diameter peers as well as the status of each, placing a heavy burden
on the endpoints as the number of nodes grows.
- Congestion control: Diameter lacks the well-defined congestion control
mechanisms found in other protocols such as SS7. For example, if an HSS has
multiple Diameter front ends, the lack of sufficient congestion control
increases the risk of a cascading HSS failure.
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