A user equipment comprising processing circuitry to: connect with an eNodeB associated with a LTE wireless network; generate packets relating to VoIP communications; and transmit the generated packets, via a wireless interface with the eNodeB, as frames using LTE-TDD communications, each of the frames including uplink data that is transmitted via TTI bundles of a particular length, wherein Semi-Persistent Scheduling, SPS, is used to transmit control information relating to transmission of the frames; characterized in that the processing circuitry is further to transmit the frames using LTE uplink/downlink configuration zero wherein: the particular length of the TTI bundles is three subframes and three concurrent HARQ processes are used for the uplink data, the particular length of the TTI bundles is six subframes and two concurrent HARQ processes are used for the uplink data, or the particular length of the TTI bundles is twelve subframes and one concurrent HARQ process is used for the uplink data; or the processing circuitry is further to transmit the frames using LTE uplink/downlink configuration six wherein: the particular length of the TTI bundles is ten subframes and one concurrent HARQ process is used for the uplink data; or the processing circuitry is further to transmit the frames using LTE uplink/downlink configuration three wherein: the particular length of the TTI bundles is three subframes and two concurrent HARQ processes are used for the uplink data, or the particular length of the TTI bundles is six subframes and one concurrent HARQ process is used for the uplink data; or the processing circuitry is further to transmit the frames using LTE uplink/downlink configuration one wherein: the particular length of the TTI bundles is two subframes and four concurrent HARQ processes are used for the uplink data, the particular length of the TTI bundles is four subframes and three concurrent HARQ processes are used for the uplink data, or the particular length of the TTI bundles is eight subframes and one concurrent HARQ process is used for the uplink data. connect with an eNodeB associated with a LTE wireless network; generate packets relating to VoIP communications; and transmit the generated packets, via a wireless interface with the eNodeB, as frames using LTE-TDD communications, each of the frames including uplink data that is transmitted via TTI bundles of a particular length, wherein Semi-Persistent Scheduling, SPS, is used to transmit control information relating to transmission of the frames; characterized in that the processing circuitry is further to transmit the frames using LTE uplink/downlink configuration zero wherein: the particular length of the TTI bundles is three subframes and three concurrent HARQ processes are used for the uplink data, the particular length of the TTI bundles is six subframes and two concurrent HARQ processes are used for the uplink data, or the particular length of the TTI bundles is twelve subframes and one concurrent HARQ process is used for the uplink data; or the particular length of the TTI bundles is three subframes and three concurrent HARQ processes are used for the uplink data, the particular length of the TTI bundles is six subframes and two concurrent HARQ processes are used for the uplink data, or the particular length of the TTI bundles is twelve subframes and one concurrent HARQ process is used for the uplink data; or the processing circuitry is further to transmit the frames using LTE uplink/downlink configuration six wherein: the particular length of the TTI bundles is ten subframes and one concurrent HARQ process is used for the uplink data; or the processing circuitry is further to transmit the frames using LTE uplink/downlink configuration three wherein: the particular length of the TTI bundles is three subframes and two concurrent HARQ processes are used for the uplink data, or the particular length of the TTI bundles is six subframes and one concurrent HARQ process is used for the uplink data; or the particular length of the TTI bundles is three subframes and two concurrent HARQ processes are used for the uplink data, or the particular length of the TTI bundles is six subframes and one concurrent HARQ process is used for the uplink data; or the processing circuitry is further to transmit the frames using LTE uplink/downlink configuration one wherein: the particular length of the TTI bundles is two subframes and four concurrent HARQ processes are used for the uplink data, the particular length of the TTI bundles is four subframes and three concurrent HARQ processes are used for the uplink data, or the particular length of the TTI bundles is eight subframes and one concurrent HARQ process is used for the uplink data. the particular length of the TTI bundles is two subframes and four concurrent HARQ processes are used for the uplink data, the particular length of the TTI bundles is four subframes and three concurrent HARQ processes are used for the uplink data, or the particular length of the TTI bundles is eight subframes and one concurrent HARQ process is used for the uplink data.