Proprietary, isolated technology currently without the backing of the larger wireless industry — will be difficult to get a foothold globally without industry support. Qualcomm has yet to trial the technology publicly keeping it tightly held until it matures in-house. Time Division Multiplexing delivery inherent in DM B transmits specific content at specific time intervals which allows the receiver to be shut down in between these intervals to save power.
Time-slicing helps conserve battery power since the receiver is only on when viewing the channel of interest. So stay tuned, as they say! Buyer's Guide. Log in.
Sign up. Apple's iOS Discord introduces a better way to organize servers. Latest in Features. Image credit:. Sponsored Links. Why switch? Broadcasting standards Fortunately, the standards battle for bringing digital TV into your home has pretty much been fought and won. In this article: features , hdtv , portable video , portablevideo. All products recommended by Engadget are selected by our editorial team, independent of our parent company.
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Court says Tesla and Musk's tweet violated labor laws. The best free-to-play games. Jaime Lloret received his M. Later, he received his M. Before concluding his PhD. He was awarded the prize of the best doctoral Student in the Telecommunications area in according to the Social Council of the Polytechnic University of Valencia. He has been working as a network designer and administrator in several companies. He also researches on educational approaches and strategies. He has been the director of many Ms. Degree Thesis. October For example, if the new network leads the current network, the mobile receiver 12 may buffer data from the new network for a time substantially equal to the lead to facilitate smooth handover from the user's perspective.
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If the new network lags the current network the mobile receiver 12 may pause the service and display an appropriate message to the user until the service in the new network catches up with the time of pause. The service may then be resumed as received from the new network.
The spreadsheet could be constructed manually by co-operation between the two DVB operators. The software may proceed to analyse the SI tables and, for each channel of the operator's network, to search for a corresponding service in the other network using a likely common identifier that becomes less restrictive with each search if no matches are found for the current channel. The likely common identifier may be changed for each search as follows:. The same process may be performed on the DVB operator's own network. If the operator's network cannot find a matching service in the other network step 2 may be followed in an attempt to identify a similar service that might be acceptable to the user.
In particular, the SI tables from the other network are parsed to look for one or more content descriptor that matches each content descriptor of each event presently ongoing in the current network. The standard recommends that content descriptors are sent in the EIT and SIT tables, although this is not compulsory and therefore these descriptors might be found in other tables. Accordingly the parsing process may begin with these two tables and if content descriptors are not found, proceed to look in all of the other tables in the transport stream s.
Once content descriptors are found, the parsing process may take each content descriptor of each current event in the operator's network and look for a match in the content descriptors of the other network. For example, a comedy programme is described by these two nibbles as 0x1 0x4. The parser may look for one or more matching comedy event i. In this way the user would be provided with a selection of potentially suitable channels to choose from during handover. If however, there is no match found when the process looks for a match with the 8-bits in the content descriptor, the process may look at step 3 for one or more event that matches the four bits of the level 1 nibble.
This level represents a more general class of event than level 2, as follows:. In contrast, level 2 represents a much finer resolution of each level 1 type as follows:. The process is quite likely to find more than one event that matches at Level 1. Accordingly, the process may try to reduce this list in the same way described above i.
Accordingly on handover the user may be presented with a list of channels to select from based on the matching list broadcast in the HAT; that list should be shorter than the total number of channels available in the new network. By mapping those events which have the same service provider, the user will be provided with a list of channels to chose from which may roughly correspond to his or her taste.
This entire process may be repeated either substantially continuously or at pre-determined intervals e. The frequency of updating may be selected by the network operator and is implementation specific. These entries can be easily filtered automatically by suitable programming of the mobile receiver For example the HAT data might be sent in under a separate PID to be filtered automatically by suitably programmed mobile receivers. The HAT 70 may be broadcast at any interval deemed appropriate by the network operator.
Accordingly the HAT may also be broadcast approximately every 2s, although this choice is implementation-specific. Optionally it is possible to use an unassigned Transmission Parameter Signalling TPS bit to flag whether or not handover data is sent in a particular transport stream. In this way the mobile receiver 12 may discover whether or not handover data is present without having to decode and read the PAT. The two broadcast type networks may each comprise a DVB-H network 84, 86 similar to that described in Fig. The CPU 94 interfaces with all of the aforementioned components to process store, access, etc.
The memory 98 stores computer executable instructions that when executed by the CPU 94 perform the mobile node method steps as described herein. These computer executable instructions may be stored in the memory of the mobile node during manufacture. The BHR 91 may be located on a server or any similar computing device anywhere within or with access to the topology of the Internet In this example, it assumed that the MN 82 is tuned to the DVB-H network 84 and is filtering a particular service from a transport stream.
At step S At step S The MN 82 proceeds as described above in order to actually perform the switch. Since the mobile receiver does not have to perform extensive operations, such as string searching the new EPG for the text identifying the channel in the current network, less battery power is consumed. Service handover time is also expected to be less than the simply string searching approach; this helps to improve the quality of the service from the user's perspective, particularly if signal strength from the current network is suddenly lost. The methods described herein are also readily scalable.
As already mentioned, the methods can be extended to more than one network overlapping partially or completely the network to which the mobile receiver is tuned. The number of entries in the HAT is linearly proportional to the number of services. This assumes that for any n each network is partly overlapped by each of the remaining n -1 networks.
In reality for large n this is unlikely and therefore this expression for T s,n represents a worst case scenario. This places an extremely low overhead on network resources, yet offers significant advantage in terms of the operation of the service from the users' perspective. If the network operators mutually agreed, a common content management system may be used to control and update the BHR To that end the MBMS may announce the multicast group as a particular service in the network and therefore may send metadata to the receivers in a suitable manner.
Such metadata may include a Session Description Protocol SDP file that describes the handover service, including details of the multicast group that each receiver must join if it wishes to receive the handover service. Following discovery of the handover service the broadcast-enabled mobile receivers join the multicast group specified in the SDP file.
The mobile receivers may then act as described above in order to execute handovers between broadcast networks whilst maintaining continuity of service.
A further possibility is that multicast groups may be defined based on Service Level Agreements SLAs between broadcast operators. A HAT may then be stored for each particular multicast group to restrict the handover possibilities available for receivers in each group based on the SLAs.asia.userengage.io/10324.php
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According the MBMS may offer more than one handover service to the mobile receivers. Handover between the SKY network and any other broadcast network is not facilitated by the HATs available to that multicast group. Some networks use encryption for pay channels. However this encryption is usually of the underlying elementary streams carrying audio and video data. The invention is applicable in other types of broadcast network, including but not limited to:. T-DMB is a digital radio transmission system for sending multimedia to mobile receivers.
Accordingly the handover data of the invention can be sent and used in a MediaFLO type network. In such a scenario it is possible for mobile receivers with appropriate interfaces such as a multi-mode receiver for example to handover from a network of one type to a network of another type, for example from a DVB-H network to a DMB network. Therefore in Fig. Many mobile receivers, known as multi-mode terminals, are now provided with more than one communication interface.
Both the WLAN and 3G interfaces provide for bi-directional wireless communication with remote networks. Accordingly there is also the possibility for a handover from a broadcast network to a bi-directional network. Further optional attributes that could be included in the HAT are: a network identifier e. Upon determination that a handover from a broadcast network to a WLAN network is prudent, the mobile receiver reads the HAT to determine the URI of the media server and any of the other optional extra attributes which can be included to which it will send a service request once connected to the WLAN.
If there are a number of bi-directional networks accessible to the mobile receiver 12 within the area of coverage of the broadcast network it is possible for the broadcast network to broadcast or for the MBMS network to provide access to only a single HAT dealing with all handover possibilities. This reveals the URI that the mobile receiver should use to request an associated service from the new network. A particular advantage of sending handover data in this way is that it does not matter whether the mobile receiver is in the first or second broadcast network.
Alternatively, the broadcast network may broadcast a number of HATs, one for each bi-directional network to which handover may be accomplished from the broadcast network. In this way each service in the broadcast network is only mentioned once in each HAT. The mobile receiver may receive the network identifier and hardware identifier from beacons transmitted by each bi-directional network. In the previous scenario, the handover data always includes space for a service identity in the new broadcast network, even if that space in the table is left blank.
However, it is envisaged that handover data may be broadcast from a broadcast network that does not include any data or space for such data about matching services in other broadcast networks. Further optional attributes that could be included in the handover data include: a base station identifier e. One particular advantage of this is that the mobile receivers do not have to be configured in advance for operation with the bi-directional network. Furthermore, in some scenarios the network identifier assists mobile receivers to differentiate between bi-directional networks of the same type.
For example, a mobile receiver may be able to detect several different WLANs in one location. Using the handover data the mobile receiver can determine whether or not one or more of those WLANs offers the same, similar or an associated service, and if so the IP address es where that service is obtainable. The handover data may also restrict the choice of bi-directional networks available to each mobile receiver.
For example, the network identifier may comprise a mapping between a first bi-directional network identifier and one or more second bi-directional network identifier, whereby a mobile receiver that has a service contract with one bi-directional network such as a mobile operator, may use said handover data to determine which other bi-directional networks are available to that mobile receiver. The first bi-directional identifier may identify the network with which the user of the mobile receiver has a service contract.
The second bi-directional network identifiers may identify those networks with which the mobile operator has service level agreements. For example, if the mobile receiver has a 3G interface, the user may have a contract with Vodafone, who in turn may have service level agreements with other providers who might provide WLAN and or femtocell coverage in certain areas.
The handover data may map Vodafone's Mobile Network Code 15 in the UK to a network identifier of each other bi-directional network with which Vodafone has a service agreement. In use, the mobile receiver uses the first bi-directional network identifier i. The match maps to a network layer address, etc. In this way the network operator is able to control using the handover data which bi-directional networks the mobile receivers can handover. If the bi-directional network to which the mobile receivers may handover comprises an MBMS, the corresponding URI in the handover data may give the location of the SDP file that describes the same, similar or an associated service to the one received from the broadcast network.
Once connected to the bi-directional network, a mobile receiver uses the URI indicated by the handover data to obtain the SDP file describing the same, similar or associated service. Using the data contained in the SDP file the mobile receiver can take the necessary steps to download or stream the service over the MBMS. In either aspect it is not essential that the media server supply, via the bi-directional network, an identical service to the one received from the broadcast network. It is possible for the media server to supply an associated or related service to the one received from the broadcast network.
For example, if the mobile receiver 12 is receiving a shopping channel from the broadcast network and the mobile receiver is taken by the user into a store operating a WLAN, the mobile receiver may handover to the WLAN. The mobile receiver 12 sends to the IP address and port number indicated in the HAT a request for the same service.
However, the media server actually delivers a television channel or other service showing goods, promotional offers, etc. The types of bi-directional network to which mobile receivers may handover in any embodiment above include, but are not limited to: 3G, 4G or any future cellular network, femtocells, WLANs, Wi-fi or WiMAX. A femtocell is a base station that incorporates all of the major components of the telecommunication infrastructure and that is designed to be used with a Ethernet or broadband connection, whereby better signal coverage and data rates on cellular frequencies can be provided inside buildings for example.
Such devices are currently available from www. The only connection from the device is at the link layer over Ethernet. Authentication takes place locally within the femtocell. In an alternative architecture for the device, the HLR resides elsewhere in the network and is under direct control of the cellular network operator. A user receiving a service from a broadcast network may handover to a femtocell when the receiver is brought within range. Accordingly to assist mobile receivers to handover from a broadcast network to a femtocell, the handover data may comprises a network identifier e.
Mobile Network Code and a base station identifier e.
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The network identifier identifies the network operator of the femtocell, and the base station identifier enables the mobile receiver to distinguish between signals from the same network but from different base stations be they from a macro cell or from a neighbouring femtocell. In any embodiment or aspect of the invention described herein, if there are mobile receivers present in the reception area that have multi-mode capability, the handover data may be transmitted to those multi-mode receivers via any network to which each of those receivers has access.
For example, in the case of handover from a broadcast network to a bi-directional network the handover data may be transmitted by any other network from which the mobile receiver can receive data.