How the Mobile Internet can be Realized through New Technologies & Applications

How the Mobile Internet can be Realized through New Technologies & Applications

Siavash(Intel) asks, "Mobile WiMAX is available today, why not use it"? He concludes, "When LTE becomes available, Intel will definitely embrace it, but we will not wait for that at the expense of WiMAX since this will only delay mobile Internet further into the future."


Introduction
Siavash Alamouti(Intel) has stated that mobile broadband needs to evolve from its current primitive state (a packet overlay of a cellular TDM network), to a wireless broadband network that can accommodate much higher bandwidth per user and overall traffic capacity.

A network optimized for mobile voice cannot be "upgraded" to handle high numbers of high bandwidth mobile Internet users that access rich multi-media content or are uploading/ downloading large video and multi-media files. The following graphic depicts the mismatch between requirements of today's voice oriented mobile networks and tomorrow's mobile broadband Internet.To achieve acceptable service levels, more spectrum is needed along with higher capacity backhaul and a different network architecture. Alamouti believes that the mobile Internet requires a technology revolution to accommodate multi-Mbps subscriber connections from many simultaneous users. Clearly, the more bandwidth available per user, the more people benefit from the mobile internet, assuming of course that the service is reasonably priced (which it's not on 3G networks).To obtain a low cost per bit, a much higher level of spectrum efficiency is needed than can be achieved by 3G or 3.5G networks.

All operators are now in agreement that 4G networks will be characterized by OFDM, MIMO, and all IP architecture. Mobile WiMAX has these features now; LTE will once it's deployed. Here's an illustration of the timeline envisioned for the mobile broadband Internet to be realized:

New 4G Applications & Services Attract More Subscribers

Here are some examples of new innovative mobile Internet applications and value added services (mobile network providers collaborating with application service providers):- A smart camera uploads photos to FLICKR via a mobile broadband network just after the photos are taken. FLICKR then manages the on-line photo album for designated friends or family members that were permitted access. The mobile network operator and FLICKR would share revenue equitably so that pricing would be attractive to the subscriber. - Location Based Service (LBS) combined with GPS. In this scenario, a subscriber searches the Internet for a leather jacket. The Mobile Internet Device (MID) advertises its location to retail merchants that stock that type of garment. Retail merchants receiving the broadcasted message have previously agreed to a revenue sharing arrangement with the mobile network operator. The merchants nearby that have the garment in stock are seen on the MID's display in order of closest distance. - A pager messenger service. In this case, the network maintains a list of the people permitted to send electronic messages to a mobile subscriber. When any of those people send a message to the subscriber, the network "wakes up" the MID and displays the message title, providing a richer service than SMS with more efficiency than contemporary Internet services using Yahoo Messenger on a MID.- Subscription based mobile video.

A user interested in a particular news program or TV channel subscribes via the mobile operator, who guarantees QOS for that channel or program.These are only some obvious examples, with many other applications and value added services that haven't even been conceived. According to Siavash, once the mobile Internet is enabled, these applications will become pervasive.Editors Note: To read about more innovative and disruptive 4G applications, please see interview part II with Jose Puthenkulam of Intel.Major Performance & Feature Upgrades Require New 4G TechnologiesSiavash lists the following key performance characteristics and features for 4G networks:- Higher peak rates and average sector throughput - Lower access and handover latency (<10> 4x better cell edge throughput) - Higher mobility (up to 500 km/hr) - Better coverage area with no signal drop- outs- Larger VoIP capacity - Enhanced broadcast and multicast services - Enhanced location based services - Deployment flexibility Technology Enablers for the Mobile Internet include:- Higher order single and multi user MIMO Techniques (4x4)- Integrated Relay- Interference management- Standards-based techniques for multi-radio coexistence- Multi-carrier (multi-channel) support- Self organization and optimization, AKA as Self Organizing Networks (SON)While most of these technology enablers are well beyond the scope and depth of this article, we'll briefly describe a few of them.1. Interference ProblemMobile WiMAX and other mobile broadband technologies support single frequency reuse throughout a given geographical area. All cells/sectors operate on one frequency channel to maximize spectrum utilization. There is often heavy interference in common frequency reuse, resulting in users at the cell edge to suffer from low connection quality. High power interferers characterize the Downlink (DL), with a limited number of interferers, e.g. maximum of eight in the IEEE 802.16m draft standard. Interference estimation- using DL preambles - may be an effective control mechanism. There are more potential interferers on the Uplink (UL) - on the order of 100s. These are low power interferers, where interference estimation is harder and must be dynamic. 2. Multi-radio co-existenceA wide variety of different radio types may exist in a given geographical area and these must co-exist without interfering with one another. This is depicted in the graphic below:3. Multi-carrier supportNetwork operators have spectrum in different frequency bands with different bandwidths. Next generation broadband wireless systems should provide flexibility to aggregate physically non-contiguous and non-uniform channels into a single radio bearer channel. This will aid in achieving efficient use of spectrum and incremental scaling of the system bandwidth. The resulting system bandwidth would no longer be limited by the size of a single radio channel. The figure below illustrates what layers and protocols are needed to achieve multi-carrier support:4. Self Organization and OptimizationIn addition to the visible features and technology upgrades required for 4G, Siavash sees several internal network control mechanisms that will be required. These will not likely be subject to standardization, but will have to be worked out between the mobile operator and network infrastructure equipment vendors. He says 4G networks should support:- Real plug and play installation of network nodes- Self-configuration of the initial installation, including the update of neighbor nodes and neighbor cells - Fast reconfiguration and compensation in failure cases- Support automated or autonomous optimization of network performance - Self-optimization of service availability, QoS, network efficiency and throughputIs LTE the Holy Grail?With the cellular industry now strongly backing LTE, Siavash asserts that LTE is a positive development but the timing is too late. He believes the cellular industry is using LTE as a way of slowing down Mobile WiMAX and is not committed to providing the capabilities of the technology near-term - even the name itself is an indication. How can we expect a technology called "Long-Term" be available in short-term? Would you deposit your savings in a long-term account when you know you need to access it today? Of course not! That is why the Mobile WiMAX industry is not stopping its work and waiting for LTE. As a result, Siavash believes that LTE will be much "Longer Term" for deployment than most pundits expect. Another important issue is that LTE is not an Evolution, but rather a "forklift upgrade" - with a new RAN, new Base Stations, new backhaul, new packet core, new network management equipment, and new spectrum all required for deployment. Mobile operators are spending billions of dollars on HSPA development today and it is unlikely that they will start investing in new spectrum and infrastructure to deploy LTE in the near future. With the exception of Verizon in the US, there are no firm dates given by mobile operators on availability of LTE services - and Verizon's end of 2010 date is for fixed LTE service- not for mobile LTE deployment.LTE modem pricing may also be an issue, if one extrapolates from already expensive 3G modem pricing. 3G-HSPA modems are priced two to three times higher than a Mobile WiMAX modems, but only deliver a peak rate of 14 M bit/sec vs. 40 M bit/sec for WiMAX. (HSPA's average throughput per sector was said to be 3-5 Mbit/sec by Alamouti). With LTE offering much higher peak rates than 3G, LTE modems will likely cost quite a bit more and therefore will be unaffordable for many potential mobile Internet subscribers.The cellular industry has always underestimated future data rate requirement. That's why 3G only targeted 100's of Kbits/sec data rate. "It's a stagnant view of user demand for mobile broadband," says Siavash.

Conclusions

Alamouti states, "As necessity is the mother of invention, WiMAX is the father of LTE." Mobile WiMAX is the first deployable wireless broadband technology based on OFDMA and MIMO. It also features a flat, all IP networks that includes technology ingredients to enable a new service paradigms and business models for truly open Internet. He believes the cellular industry has not delivered to the pent up consumer demand for mobile Internet. "We require a short-term revolution not a long-term evolution". He believes the battle between radio technologies need to end and the industry needs to bring affordable Internet access to the consumer in order to stimulate the economy globally. Siavash asks, "Mobile WiMAX is available today, why not use it"? He concludes, "When LTE becomes available, Intel will definitely embrace it, but we will not wait for that at the expense of WiMAX since this will only delay mobile Internet further into the future."