While mobile data services are hardly new, most of them have largely been business applications such as e-mail which involve relatively small volumes of data, which most networks have so far been able to cope with.

However, the introduction of mobile smartphones such as the Apple iPhone and its imitators which have followed, have enabled consumers to easily access high-volume content and applications such as streaming videos, upload and download music, video and other bulky content which have put a strain on the capacities of cellular networks.

During the time when voice was the primary use of cellular communications, revenue tended to rise in tandem with traffic, while remaining ahead of costs but now, especially with flat rate data plans and the increased use of data, revenue growth has been minimal, while costs continue to rise along with traffic volume, putting pressure on operators to increase their network capacity at considerable cost, with little  expected return-on-investment (RoI).

However, Alcatel-Lucent believes its zero touch photonics, packet optical transport, microwave packet radio and intelligent optical core solutions can help operators keep costs below revenues despite growing traffic.

Much of the data flowing through current networks is relatively trivial and time-insensitive and current fibre switching and routing equipment using wavelength division multiplexing (WDM) are useful but not very flexible and involve high operating costs since they require manual intervention to re-configure and scale up.

“However, zero touch photonics lets the equipment  be re-configured centrally from the network operations centre and to re-route traffic automatically in case a fibre is cut,” said Nicolas Almendro, vice-president, Alcatel-Lucent, Asia-Pacific Optics Competence Centre.

Over the last 20 years, optical transport has employed the Synchronous Digital Hierarchy (SDH) multiplexing protocol which was designed to carry time-division multiplexed (TDM) traffic which is a legacy of the voice days and hence more suitable for voice traffic.

TDM was developed to optimise use especially of long distance links by carrying digitised slices of voice in dedicated time slots within the connection. GSM phones also employ TDM to enable up to eight phones to use a single carrier frequency at the same time.

However, with today's burgeoning growth in data, SDH is faced with problems of scalability to be able to cope.

Alcatel-Lucent's solution for this is to use Transport – Multi-Protocol Label Switching (T-MPLS) designed by standards bodies to provide packet optical transport with the same security, operational administration and maintenance as SDH but optimised for data.

One of the problems of Internet Protocol (IP) networks is their non-deterministic nature – ie. where each of the data packets related to a file or an application takes different routes through the network to their final destination where they are re-assembled.

While this may be fine in the case of an e-mail or file transfer where minor delays are not an issue, it can become a problem with time-critical traffic such as voice-over-IP call, streaming audio or video where delays, especially when the network is congested, resulting in unintelligible conversation or a bad viewing experience.

T-MPLS is deterministic, much like legacy circuit-switched telephone systems, where the route through the Internet between the two communicating ends is fixed beforehand to ensure smooth traffic flow and quality of service (QoS).

Also in the case of a fibre being cut, T-MPLS can switch to an alternative route in under 50 milliseconds, which is hardly noticeable in the case of voice or video.

Even SDH fibre networks consist of at least two fibre rings or mesh interconnections to provide alternative routes in case of a fibre cut and Maxis has a mesh network at the core which uses Alcatel-Lucent interconnects.

Microwave packet radio is similar to packet optical transport but a big issue is that microwaves tend to be affected by weather conditions, with loss of connection.

“However, the speed of microwave packet radio can be reduced with higher revenue generating voice traffic prioritised over lower revenue data and Alcatel-Lucent's system uses adaptive modulation based on packet radio to prioritise certain types of IP traffic.

Intelligent optical core mesh switching is becoming increasingly popular as it provides more alternatives but such switching is more complex, requires more intelligence and employs Generalised MPLS, which is more related to signalling.

With G-MPLS, all nodes in the network know of its topology and all nodes make decisions at the same time and know how to route traffic using distributed intelligence.

Traditional MPLS is IP-MPLS which has features of layers 2 (Data Link Layer) and 3 (Network Layer) of the Open Systems Interconnect (OSI) model. On the other hand, T-MPLS operates at layer 2 while G-MPLS is layer-agnostic and works at layers 0 (zero), 1, 2, and 3.

In optical communications, Layer 0 is the photonic layer without the electronics, while Layer 1 includes TDM, SDH, OTN and so on.

“With these four areas of investment, Alcatel-Lucent covers all needs of operators with regards to transport,” said Almendro.

Another issue which concerns operators is power consumption, where the power consumption of communications equipment comprises between 2% to 4% of a country's total power consumed and Alcatel-Lucent can help reduce not only power consumption but also the physical footprint of equipment.

Terabit/s chip

On 21 January, Alcatel-Lucent announced its 1870 Transport Tera Switch (1870 TTS) which it claims makes it easier and cheaper for service providers to manage the dramatic growth of IP traffic in backbone networks.
The 1870 TTS is an optical core switching platform based on the next-generation Optical Transport Network (OTN) standard.

“It's the first to contain a 1Tb/s (terabit/sec) switch in a single chip, developed by Alcatel-Lucent's Bell Labs,” said Almendro.

The chip allows universal switching – at 1 TBits/s -- of any traffic mix on a single chip. It scales as high as four Tbit/s in its first release and is “hardware ready” to support 8 Tbit/s.

The 1880 TTS gives operators the flexibility to transport IP traffic, including video, at the most cost-effective layer of the network while increasing profitability by freeing up bandwidth for higher value services, while it also has innovative features which simplify network operations and increase scalability and power efficiency to the highest levels in the industry.

“Continuously increasing core router capacity is expensive and time consuming. A cost efficient, next-generation OTN infrastructure is required to selectively identify and handle traffic flows to minimize transit through the core router network and eliminate unnecessary consumption of network resources,” said Almendro.

Its also a critical component of Alcatel-Lucent’s Converged Backbone Transformation solution which when combined with Alcatel-Lucent's expertise, helps service providers use their network resources as efficiently as possible, freeing bandwidth for higher-value services and reducing their carbon footprint.

The 1870 TTS supports multiple transport networking options, including OTN, WDM, Carrier Ethernet and SONET/SDH, and offers GMPLS/Automatically Switched Optical Network (GMPLS/ASON) control plane intelligence for added-value applications such as advanced restoration, resource virtualisation and cross-layer automation for seamless integration into existing assets, which enables highly resilient transport and dynamic bandwidth provisioning across multiple transport networking layers for the highest network efficiency.

Additionally, the 1870 TTS provides multiple bandwidth management options, giving service providers the flexibility to move transit traffic across lower cost optical infrastructure as appropriate according to service mix and IP traffic destination.

It features a variable rate “virtual container” technology called optical data unit flex (ODUFlex), which allows universal traffic grooming between optical transport equipment and IP routers in a manner that efficiently addresses incremental bandwidth growth, in steps as small as 1Gbit/s, thus enabling higher network monetisation, greater resiliency and lower complexity, culminating in capital expenditure cost savings, as well as saving in power, space and network operations.

“Its footprint is a mere 600 x 300mm compared to equipment which occupied a whole floor previously and it has 3,000 times the capacity of transport systems 20 years ago with speeds of 140Mb/s,” said Almendro.

The Alcatel-Lucent 1870 TTS is in trials with customers and has already been selected by leading service providers worldwide, including in Malaysia.