Everything you need to know about WiMAX
WiMAX and LTE
WiMAX and LTE
One of the most common issues of discussion one finds today in either WiMAX or 3G fora are the technology growth path, will it be LTE or Mobile WiMAX? In fact this question has also led to a considerable debate amongst the regulators in different countries as it has a bearing on the way future resources such as spectrum need to be allocated.
It must be said at the outset that the LTE is the path most carriers ( 3G and CDMA) are planning to follow for the present, at least till they can see something better in Mobile WiMAX. All the carriers have been following the 3GPP ( and 3GPP2) upgrade paths, which now at HSUPA and EV-DO will take them to LTE and UMB.
Because the mobile community is very large and 3GPP is their own body for evolution, it is not surprising that almost all carriers have announced the upgrade paths as LTE. This is proving to be a hurdle for the uptake of Mobile WiMAX by many networks as they see heir upgrade paths as those specified as 3GPP.
But the fact is that LTE is still not yet fully defined, let alone tried as per frozen standards. This leaves many areas which could face delays as technology moves from Labs to trials and on to commercial use. Mobile WiMAX is right now fathered mostly by Intel and a few others, but its path is differnt and it has many advantages, particulary in the technology and availability of spectrum. This makes possible high bandwidth open applications, more than what can be said of even HSPA. A large ecosystem has also been built around Mobile WiMAX after over 300 trials. The ecosystem includes the chipsets, CPEs, plug in devices as well as Wave 2 compliant base stations, test apparatus and implementation aids.
Is is possible to harmonize 3GPP and mobile WiMAX or LTE and Mobile WiMAX? Potentially it has become easier now after the WRC has adopted OFDMA-TDD as one of the approved interfaces for IMT. This makes it possible for 3G ( and evolved systems including LTE) to coexist in different parts of the network as the higher architectural layers can follow the 3GPP.
The question is why would 3G operators use mobile WiMAX, if at all? I would say that there are many reasons for this. One, the Mobile WiMAX technology is now available including the wave 2 devices. So if the operators really want to grow on data, they can use the more easily available spectrum for Mobile WiMAX than that available for 3G or LTE. It also allows a second path to the internet, the first being via their own GNA techniques. Secondly WiMAX features are much more powerful for multimedia transmission ( such as support for MBS and service flows). Hence there is a good case for dual mode devices.
There are of course still many issues which the WiMAX forum needs to hasten to make Mobile WiMAX viable. They are seen as too slow in certifications and defining the higher layers of WiMAX. The technology also has some proving to do in so far as more advanced implementations such as those involving SFNs and micro-diversity handover are concerned.Potentially latency is higher in Mobile WiMAX particularly when it is operated as an SFN for MBS type operations. The synchronization is by means of IEEE 1588 precision timing protocol with the GPS source, which makes it +- 10 microseconds as compared to 2-3 microseconds for LTE and EVDO/HSPA, which are also based on the use of a GPS source. This means that multidiversity operation of Mobile WiMAX stations is more complex and can be subject to loss of synchronism or collision in transmissions. But it is compensated by its more advanced features of classes of service and support of service flows. We should soon have more data on this when more implementations are on the ground for MBS, though as yet they seem to be very few. This is also because of the WiMAX forum not being able to quickly move ahead on the network architectures.3GPP and LTE definitely score on this account as the architectures are fully defined up to the application level. This is the main reason why WiMAX applications are flagging and most operators who take up implementations based on WiMAX are in a quandry on how to integrate it and develop applications over it. Many of the MBS implementations are coming out as proprietary and not all operators are implementing them in the same way.
Proponents of LTE claim that it has an edge so far as latency is concerned, but this is based on the technology guidance, no one has seen it yet. But as the LTE standards move ahead, there is a good case for better harmonization of standards with WiMAX, which in any event is one of the permitted air interfaces in the network. We will need to also see how the Flash OFDM and OFDMA-TDD technologies can coexist and what implications arise from a commercial viewpoint as well.
There is however a much stronger case for Mobile WiMAX today. No wireless technology has been tested so widely as mobile WiMAX has, nor can any technology claim to deliver high quality multimedia with assured QoS to hundreds of thousands of devices as Mobile WiMAX can. The close to a million WiFi hot spots are a testimony to the fact that Wireless does provide value depite what mobile networks can offer and this remains the key reason why Mobile WiMAX will be used extensively in the near future.
One of the most common issues of discussion one finds today in either WiMAX or 3G fora are the technology growth path, will it be LTE or Mobile WiMAX? In fact this question has also led to a considerable debate amongst the regulators in different countries as it has a bearing on the way future resources such as spectrum need to be allocated.
It must be said at the outset that the LTE is the path most carriers ( 3G and CDMA) are planning to follow for the present, at least till they can see something better in Mobile WiMAX. All the carriers have been following the 3GPP ( and 3GPP2) upgrade paths, which now at HSUPA and EV-DO will take them to LTE and UMB.
Because the mobile community is very large and 3GPP is their own body for evolution, it is not surprising that almost all carriers have announced the upgrade paths as LTE. This is proving to be a hurdle for the uptake of Mobile WiMAX by many networks as they see heir upgrade paths as those specified as 3GPP.
But the fact is that LTE is still not yet fully defined, let alone tried as per frozen standards. This leaves many areas which could face delays as technology moves from Labs to trials and on to commercial use. Mobile WiMAX is right now fathered mostly by Intel and a few others, but its path is differnt and it has many advantages, particulary in the technology and availability of spectrum. This makes possible high bandwidth open applications, more than what can be said of even HSPA. A large ecosystem has also been built around Mobile WiMAX after over 300 trials. The ecosystem includes the chipsets, CPEs, plug in devices as well as Wave 2 compliant base stations, test apparatus and implementation aids.
Is is possible to harmonize 3GPP and mobile WiMAX or LTE and Mobile WiMAX? Potentially it has become easier now after the WRC has adopted OFDMA-TDD as one of the approved interfaces for IMT. This makes it possible for 3G ( and evolved systems including LTE) to coexist in different parts of the network as the higher architectural layers can follow the 3GPP.
The question is why would 3G operators use mobile WiMAX, if at all? I would say that there are many reasons for this. One, the Mobile WiMAX technology is now available including the wave 2 devices. So if the operators really want to grow on data, they can use the more easily available spectrum for Mobile WiMAX than that available for 3G or LTE. It also allows a second path to the internet, the first being via their own GNA techniques. Secondly WiMAX features are much more powerful for multimedia transmission ( such as support for MBS and service flows). Hence there is a good case for dual mode devices.
There are of course still many issues which the WiMAX forum needs to hasten to make Mobile WiMAX viable. They are seen as too slow in certifications and defining the higher layers of WiMAX. The technology also has some proving to do in so far as more advanced implementations such as those involving SFNs and micro-diversity handover are concerned.Potentially latency is higher in Mobile WiMAX particularly when it is operated as an SFN for MBS type operations. The synchronization is by means of IEEE 1588 precision timing protocol with the GPS source, which makes it +- 10 microseconds as compared to 2-3 microseconds for LTE and EVDO/HSPA, which are also based on the use of a GPS source. This means that multidiversity operation of Mobile WiMAX stations is more complex and can be subject to loss of synchronism or collision in transmissions. But it is compensated by its more advanced features of classes of service and support of service flows. We should soon have more data on this when more implementations are on the ground for MBS, though as yet they seem to be very few. This is also because of the WiMAX forum not being able to quickly move ahead on the network architectures.3GPP and LTE definitely score on this account as the architectures are fully defined up to the application level. This is the main reason why WiMAX applications are flagging and most operators who take up implementations based on WiMAX are in a quandry on how to integrate it and develop applications over it. Many of the MBS implementations are coming out as proprietary and not all operators are implementing them in the same way.
Proponents of LTE claim that it has an edge so far as latency is concerned, but this is based on the technology guidance, no one has seen it yet. But as the LTE standards move ahead, there is a good case for better harmonization of standards with WiMAX, which in any event is one of the permitted air interfaces in the network. We will need to also see how the Flash OFDM and OFDMA-TDD technologies can coexist and what implications arise from a commercial viewpoint as well.
There is however a much stronger case for Mobile WiMAX today. No wireless technology has been tested so widely as mobile WiMAX has, nor can any technology claim to deliver high quality multimedia with assured QoS to hundreds of thousands of devices as Mobile WiMAX can. The close to a million WiFi hot spots are a testimony to the fact that Wireless does provide value depite what mobile networks can offer and this remains the key reason why Mobile WiMAX will be used extensively in the near future.
Replies to This Discussion
-
Permalink Reply by Alan J Weissberger on
-
Here'a an update on this topic:
3G and LTE squeeze WiMAX
http://viodi.com/2009/02/21/3g-and-lte-squeeze-wimax-is-the-market-...'
After reading my article please post comments in the box below it (there are several comments already)
© 2010 Created by WiMAX Broadband Solutions
